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Zhao H, Dai S, Ouyang K, Zhu S, Yin H, Li Z, Chen Z. High-power and narrow-linewidth nanosecond pulsed intracavity crystalline Raman laser operating at 1.7 µm. OPTICS EXPRESS 2024; 32:20852-20861. [PMID: 38859455 DOI: 10.1364/oe.527203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Accepted: 05/14/2024] [Indexed: 06/12/2024]
Abstract
We report on a high-power and narrow-linewidth nanosecond pulsed intracavity crystalline Raman laser at 1.7 µm. Driven by an acousto-optically Q-switched 1314 nm two-crystal Nd:YLF laser, the highly efficient cascaded YVO4 Raman laser at 1715nm was obtained within the well-designed L-shaped resonator. Thanks to the absence of spatial hole burning in the stimulated Raman scattering process, significant spectral purification of second-Stokes radiation was observed by incorporating a fused silica etalon in the high-Q fundamental cavity. Under the repetition rate of 4 kHz, the highest average output power for single longitudinal mode operation was up to 2.2 W with the aid of precision vibration isolation and precision temperature controlling, corresponding to the pulse duration of ∼2.8 ns and the spectral linewidth of ∼330 MHz. Further increasing the launched pump power, the second-Stokes laser tended toward be always multimode, and the maximum average output power amounted to 4.8 W with the peak power of ∼0.8 MW and the spectral linewidth of ∼0.08 nm. The second-Stokes emission was near diffraction limited with M2 < 1.4 across the whole pump power range.
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Li Q, Zhang P, Fan Y, Ning Y, Wei J, Tong S. 1.7 µm gain-switched and mode-locked hybrid Tm-Ho codoped fiber laser signal generation and optimization. APPLIED OPTICS 2022; 61:455-462. [PMID: 35200882 DOI: 10.1364/ao.446575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 12/16/2021] [Indexed: 06/14/2023]
Abstract
We propose and experimentally demonstrate 1.7 µm gain-switched and mode-locked hybrid laser signal generation using a modulated pump and the nonlinear polarization rotation (NPR) effect. In the laser scheme, a 1.55 µm amplified modulated optical signal was used as a homemade pump. A bidirectional pumping configuration was adopted by splitting the homemade pump. A 1 m long thulium-holmium (Tm-Ho) codoped fiber was used as the gain medium. A fiber Bragg grating was employed as a spectral filter. The mode-locked laser pulse was obtained with a central wavelength of 1724 nm. The repetition rate was 11.81 MHz and the pulse width was 65.27 ps. Additionally, the gain-switched pulse sequences with a repetition rate from 50 kHz to 200 kHz were obtained by the modulated pump. Moreover, the mode-locked pulse train was filtered and modulated by the shape of the gain-switched pulse, and the hybrid pulse train was then obtained. Furthermore, the hybrid laser signals were analyzed and optimized by applying different waveforms of the modulated pump. The experimental results showed that the generated laser pulse driven by the sinusoidal signal has a better SNR (49.39 dB).
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Fan Y, Ma Q, Li M, Luan D, Kang H. Quantitative investigation of laser ablation based on real-time temperature variations and OCT images for laser treatment applications. Lasers Surg Med 2021; 54:459-473. [PMID: 34779006 DOI: 10.1002/lsm.23491] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/03/2021] [Accepted: 11/01/2021] [Indexed: 12/28/2022]
Abstract
BACKGROUND AND OBJECTIVE Lasers are widely employed in clinical applications. In vivo monitoring of real-time information about different-wavelength laser surgeries would provide important surgical feedback for surgeons or clinical therapy instruments. However, the quantitative effect of laser ablation or vaporization still needs to be further explored and investigated. Here, we investigate and quantitatively evaluate the ablation variations and morphological changes of two laser ablation models: point- and sweeping-based models. METHODS An infrared thermal imager was used to monitor the temperature variations, and curve fitting was used to build the relationship between the laser radiation duration/sweeping speed and quantitative parameters of the ablated areas. Optical coherence tomography (OCT) images were used to visualize the inner structure and evaluate the depth of the ablated craters. Optical attenuation coefficients (OACs) were computed to characterize the normal and ablated tissues. RESULTS The results demonstrated that there was a good linear relationship between radiation duration and temperature variation. Similarly, a linear relationship was observed between the sweeping speed and quantitative parameters of craters or scratches (width and depth). The mean OAC of normal tissues was significantly distinguished from the mean OACs of the ablated craters or scratches. CONCLUSION Laser ablation was investigated based on a quantitative parameter analysis, thermal detection, and OCT imaging, and the results successfully demonstrated that there is a linear relationship between the laser parameters and quantitative parameters of the ablated tissues under the current settings. Such technology could be used to provide quantitative solutions for exploring the laser-tissue biological effect and improve the performance of medical image-guided laser ablation in the future.
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Affiliation(s)
- Yingwei Fan
- Institute of Engineering Medicine, Beijing Institute of Technology, Beijing, China
| | - Qiong Ma
- Beijing Institute of Radiation Medicine, Beijing, China
| | - Mengsha Li
- Beijing Institute of Radiation Medicine, Beijing, China
| | - Dian Luan
- Beijing Institute of Radiation Medicine, Beijing, China
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Huang Z, Boscolo S, Huang Q, Xing Z, Yan Z, Chen T, Liu Y, Mou C. Generation of 64-fs L-band stretched pulses from an all-fibre Er-doped laser. OPTICS EXPRESS 2021; 29:34892-34899. [PMID: 34808938 DOI: 10.1364/oe.434546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 09/23/2021] [Indexed: 06/13/2023]
Abstract
We demonstrate an L-band all-fibre erbium-doped laser mode locked by nonlinear polarisation rotation and working in the stretched-pulse regime. The use of a single segment of gain fibre with appropriate length and dispersion and a Brewster fibre grating optimised for the L band as an in-fibre polariser enables the generation of pulses at 1.59-μm central wavelength, which can be linearly compressed to 64-fs duration. Numerical simulations of the laser model support our experimental findings. Our laser design gives a route towards low-cost and low-complexity fibre-integrated laser sources for applications requiring L-band ultrashort pulses.
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Ota K, Ono J, Mori H, Ono H, Koyama O, Ikeda K, Yamada M. 1.8 µm band broadband hybrid light source employing a combination of a super luminescent diode and thulium-doped fiber amplifier. APPLIED OPTICS 2021; 60:9419-9424. [PMID: 34807081 DOI: 10.1364/ao.439019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 09/24/2021] [Indexed: 06/13/2023]
Abstract
We have proposed a broadband hybrid light source that combines a super luminescent diode (SLD) and thulium-doped fiber amplifier (TDFA) and operates in the 1.8 µm band. This light source can improve the characteristics of the output spectrum by amplifying the output light of the SLD with TDFA. In this study, we investigate the dependence of the output spectral characteristics of the hybrid broadband light source on the thulium-doped fiber (TDF) length used in the TDFA as well as the output spectra of three newly developed SLDs of 1660, 1690, and 1730 nm bands. In the evaluation of the output bandwidth, there are various definitions of output bandwidth, but we adopted the bandwidth with power density of over -40dBm/0.1nm. This is because it is possible to evaluate in this band with a dynamic range of "30 dB/0.1 nm" by using a general optical spectrum analyzer. The hybrid light source achieves the bandwidth of 332 nm, from 1579 to 1911 nm, and a high total output power of over 15 dBm. The maximum ripple was less than ∼0.1dB, which is similar to the maximum value of that of the SLD, without any deterioration in the ripple characteristics owing to the hybrid configuration of the SLD and TDFA.
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Pei W, Li H, Huang W, Wang M, Wang Z. All-Fiber Tunable Pulsed 1.7 μm Fiber Lasers Based on Stimulated Raman Scattering of Hydrogen Molecules in Hollow-Core Fibers. Molecules 2021; 26:4561. [PMID: 34361709 PMCID: PMC8348020 DOI: 10.3390/molecules26154561] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 07/19/2021] [Accepted: 07/26/2021] [Indexed: 11/17/2022] Open
Abstract
Fiber lasers that operate at 1.7 μm have important applications in many fields, such as biological imaging, medical treatment, etc. Fiber gas Raman lasers (FGRLs) based on gas stimulated Raman scattering (SRS) in hollow-core photonic crystal fibers (HC-PCFs) provide an elegant way to realize efficient 1.7 μm fiber laser output. Here, we report the first all-fiber structure tunable pulsed 1.7 μm FGRLs by fusion splicing a hydrogen-filled HC-PCF with solid-core fibers. Pumping with a homemade tunable pulsed 1.5 μm fiber amplifier, efficient 1693~1705 nm Stokes waves are obtained by hydrogen molecules via SRS. The maximum average output Stokes power is 1.63 W with an inside optical-optical conversion efficiency of 58%. This work improves the compactness and stability of 1.7 μm FGRLs, which is of great significance to their applications.
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Affiliation(s)
- Wenxi Pei
- College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China; (W.P.); (H.L.); (W.H.); (M.W.)
- Hunan Provincial Key Laboratory of High Energy Laser Technology, Changsha 410073, China
| | - Hao Li
- College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China; (W.P.); (H.L.); (W.H.); (M.W.)
- Hunan Provincial Key Laboratory of High Energy Laser Technology, Changsha 410073, China
| | - Wei Huang
- College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China; (W.P.); (H.L.); (W.H.); (M.W.)
- State Key Laboratory of Pulsed Power Laser Technology, Changsha 410073, China
| | - Meng Wang
- College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China; (W.P.); (H.L.); (W.H.); (M.W.)
- Hunan Provincial Key Laboratory of High Energy Laser Technology, Changsha 410073, China
- State Key Laboratory of Pulsed Power Laser Technology, Changsha 410073, China
| | - Zefeng Wang
- College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China; (W.P.); (H.L.); (W.H.); (M.W.)
- Hunan Provincial Key Laboratory of High Energy Laser Technology, Changsha 410073, China
- State Key Laboratory of Pulsed Power Laser Technology, Changsha 410073, China
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He J, Song R, Yang W, Hou J. High-efficiency ultra-compact near-infrared supercontinuum generated in an ultrashort cavity configuration. OPTICS EXPRESS 2021; 29:19140-19146. [PMID: 34154155 DOI: 10.1364/oe.425948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 05/27/2021] [Indexed: 06/13/2023]
Abstract
We report a novel method to generate near-infrared supercontinuum (SC) in an ultrashort cavity configuration with only 11.5 m. With the continuous laser diode pump, a near-infrared SC with 26.8 W average output power and a spectrum ranging from 900 nm to 2000nm is demonstrated, and the laser diode pump to supercontinuum conversion efficiency is up to 60%. The spectral and power characteristics of the generated SC under different lengths of germanium-doped fiber (GDF) were carefully studied. This near-infrared SC generation method has the advantages of simple structure, low cost and good stability and also possesses the shortest fiber laser cavity length ever reported to the best of our knowledge.
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Kufcsák A, Bagnaninchi P, Erdogan AT, Henderson RK, Krstajić N. Time-resolved spectral-domain optical coherence tomography with CMOS SPAD sensors. OPTICS EXPRESS 2021; 29:18720-18733. [PMID: 34154122 DOI: 10.1364/oe.422648] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 05/14/2021] [Indexed: 06/13/2023]
Abstract
We present a first spectral-domain optical coherence tomography (SD-OCT) system deploying a complementary metal-oxide-semiconductor (CMOS) single-photon avalanche diode (SPAD) based, time-resolved line sensor. The sensor with 1024 pixels achieves a sensitivity of 87 dB at an A-scan rate of 1 kHz using a supercontinuum laser source with a repetition rate of 20 MHz, 38 nm bandwidth, and 2 mW power at 850 nm centre wavelength. In the time-resolved mode of the sensor, the system combines low-coherence interferometry (LCI) and massively parallel time-resolved single-photon counting to control the detection of interference spectra on the single-photon level based on the time-of-arrival of photons. For proof of concept demonstration of the combined detection scheme we show the acquisition of time-resolved interference spectra and the reconstruction of OCT images from selected time bins. Then, we exemplify the temporal discrimination feature with 50 ps time resolution and 249 ps timing uncertainty by removing unwanted reflections from along the optical path at a 30 mm distance from the sample. The current limitations of the proposed technique in terms of sensor parameters are analysed and potential improvements are identified for advanced photonic applications.
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Highly Efficient Nanosecond 1.7 μm Fiber Gas Raman Laser by H2-Filled Hollow-Core Photonic Crystal Fibers. CRYSTALS 2020. [DOI: 10.3390/cryst11010032] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We report here a high-power, highly efficient, wavelength-tunable nanosecond pulsed 1.7 μm fiber laser based on hydrogen-filled hollow-core photonic crystal fibers (HC-PCFs) by rotational stimulated Raman scattering. When a 9-meter-long HC-PCF filled with 30 bar hydrogen is pumped by a homemade tunable 1.5 μm pulsed fiber amplifier, the maximum average Stokes power of 3.3 W at 1705 nm is obtained with a slope efficiency of 84%, and the slope efficiency achieves the highest recorded value for 1.7 μm pulsed fiber lasers. When the pump pulse repetition frequency is 1.3 MHz with a pulse width of approximately 15 ns, the average output power is higher than 3 W over the whole wavelength tunable range from 1693 nm to 1705 nm, and the slope efficiency is higher than 80%. A steady-state theoretical model is used to achieve the maximum Stokes power in hydrogen-filled HC-PCFs, and the simulation results accord well with the experiments. This work presents a new opportunity for highly efficient tunable pulsed fiber lasers at the 1.7 μm band.
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Fan Y, Ma Q, Xin S, Peng R, Kang H. Quantitative and Qualitative Evaluation of Supercontinuum Laser‐Induced Cutaneous Thermal Injuries and Their Repair With OCT Images. Lasers Surg Med 2020. [DOI: 10.1002/lsm.23287] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Yingwei Fan
- Beijing Institute of Radiation Medicine Beijing 100850 China
| | - Qiong Ma
- Beijing Institute of Radiation Medicine Beijing 100850 China
| | - Shenghai Xin
- Department of Biomedical Engineering School of Medicine, Tsinghua University Beijing 100084 China
| | - Ruiyun Peng
- Beijing Institute of Radiation Medicine Beijing 100850 China
| | - Hongxiang Kang
- Beijing Institute of Radiation Medicine Beijing 100850 China
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11
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Sanchez-Cano A, Saldaña-Díaz JE, Perdices L, Pinilla I, Salgado-Remacha FJ, Jarabo S. Measurement method of optical properties of ex vivo biological tissues of rats in the near-infrared range. APPLIED OPTICS 2020; 59:D111-D117. [PMID: 32400631 DOI: 10.1364/ao.384614] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/06/2020] [Indexed: 06/11/2023]
Abstract
An optical fiber-based supercontinuum setup and a custom-made spectrophotometer that can measure spectra from 1100 to 2300 nm, are used to describe attenuation properties from different ex vivo rat tissues. Our method is able to differentiate between scattering and absorption coefficients in biological tissues. Theoretical assumptions combined with experimental measurements demonstrate that, in this infrared range, tissue attenuation and absorption can be accurately measured, and scattering can be described as the difference between both magnitudes. Attenuation, absorption, and scattering spectral coefficients of heart, brain, spleen, retina, and kidney are given by applying these theoretical and experimental methods. Light through these tissues is affected by high scattering, resulting in multiple absorption events, and longer wavelengths should be used to obtain lower attenuation values. It can be observed that the absorption coefficient has a similar behavior in the samples under study, with two main zones of absorption due to the water absorption bands at 1450 and 1950 nm, and with different absolute absorption values depending on the constituents of each tissue. The scattering coefficient can be determined, showing slight differences between retina and brain samples, and among heart, spleen and kidney tissues.
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12
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Li X, Zhang P, Wu D, Han K, Tong S, Jiang H. Single-/dual-pulse repetition rate variable supercontinuum light source with peak wavelength around 1.7 µm using a modulated pump. APPLIED OPTICS 2020; 59:3458-3466. [PMID: 32400461 DOI: 10.1364/ao.387225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 03/06/2020] [Indexed: 06/11/2023]
Abstract
A single-/dual-pulse repetition rate variable supercontinuum (SC) light source (SLS) with a peak wavelength of around 1.7 µm (SLS around 1.7 µm) is proposed and experimentally demonstrated. In our scheme, a 1.5 µm modulated pump source included a laser and an intensity modulator (IM). The pump source can generate pulse trains with different repetitions and pulse durations. A 1 km high nonlinear fiber (HNLF) was used as the nonlinear gain medium. A picosecond-pulsed SC signal was obtained by pumping the HNLF, and a wavelength division multiplexer was used for filtering residual pump. Additionally, a Sagnac loop was applied to create a multiwavelength pulse SC light source. The generated SC source covered from 1.59 to 1.96 µm, and its peak wavelength was around 1.7 µm. The single-/dual-pulse train can be produced and switched by adjusting the direct current bias and radio frequency driving voltages of the input signal to the IM. When the repetition rate of the generated pulse train was between 170 MHz and 2 GHz, the pulse duration of the dual-pulse train was between 60 ps and 180 ps. Additionally, the duty cycle of the dual-pulse operation was 40%. The single pulse SLS, around 1.7 µm, can be a choice to improve optical coherence tomography (OCT) performance, and the dual-pulse source will be a reference for laser drilling applications.
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Qin Y, Batjargal O, Cromey B, Kieu K. All-fiber high-power 1700 nm femtosecond laser based on optical parametric chirped-pulse amplification. OPTICS EXPRESS 2020; 28:2317-2325. [PMID: 32121924 PMCID: PMC7053498 DOI: 10.1364/oe.384185] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/04/2020] [Accepted: 01/06/2020] [Indexed: 05/09/2023]
Abstract
We present the design and construction of an all-fiber high-power optical parametric chirped-pulse amplifier working at 1700 nm, an important wavelength for bio-photonics and medical treatments. The laser delivers 1.42 W of output average power at 1700 nm, which corresponds to ∼40 nJ pulse energy. The pulse can be de-chirped with a conventional grating pair compressor to ∼450 fs. Furthermore, the laser has a stable performance with relative intensity noise typically below the -130 dBc/Hz level for the idler pulses at 1700 nm from 10kHz to 16.95 MHz, half of the laser repetition rate f/2.
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Affiliation(s)
- Yukun Qin
- College of Optical Sciences, University of Arizona, 1630 E. University Blvd, Tucson, Arizona 85721, USA
| | - Orkhongua Batjargal
- College of Optical Sciences, University of Arizona, 1630 E. University Blvd, Tucson, Arizona 85721, USA
| | - Benjamin Cromey
- College of Optical Sciences, University of Arizona, 1630 E. University Blvd, Tucson, Arizona 85721, USA
| | - Khanh Kieu
- College of Optical Sciences, University of Arizona, 1630 E. University Blvd, Tucson, Arizona 85721, USA
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Signal-to-background ratio and lateral resolution in deep tissue imaging by optical coherence microscopy in the 1700 nm spectral band. Sci Rep 2019; 9:16041. [PMID: 31690729 PMCID: PMC6831679 DOI: 10.1038/s41598-019-52175-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 10/09/2019] [Indexed: 11/08/2022] Open
Abstract
We quantitatively investigated the image quality in deep tissue imaging with optical coherence microscopy (OCM) in the 1700 nm spectral band, in terms of the signal-to-background ratio (SBR) and lateral resolution. In this work, to demonstrate the benefits of using the 1700 nm spectral band for OCM imaging of brain samples, we compared the imaging quality of OCM en-face images obtained at the same position by using a hybrid 1300 nm/1700 nm spectral domain (SD) OCM system with shared sample and reference arms. By observing a reflective resolution test target through a 1.5 mm-thick tissue phantom, which had a similar scattering coefficient to brain cortex tissue, we confirmed that 1700 nm OCM achieved an SBR about 6-times higher than 1300 nm OCM, although the lateral resolution of the both OCMs was similarly degraded with the increase of the imaging depth. Finally, we also demonstrated high-contrast deep tissue imaging of a mouse brain at a depth up to 1.8 mm by using high-resolution 1700 nm SD-OCM.
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Pham TT, Chen L, Heidari AE, Chen JJ, Zhukhovitskaya A, Li Y, Patel U, Chen Z, Wong BJ. Computational analysis of six optical coherence tomography systems for vocal fold imaging: A comparison study. Lasers Surg Med 2019; 51:412-422. [PMID: 30681167 PMCID: PMC6658351 DOI: 10.1002/lsm.23060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/30/2018] [Indexed: 11/09/2022]
Abstract
OBJECTIVES There have been many advancements in laryngeal imaging using optical coherence tomography (OCT), with varying system design and probes for use in research, office, and operating room settings. We evaluated the performance of six distinct OCT systems in imaging porcine vocal folds (cords) using computational image processing and segmentation. METHODS Porcine vocal folds were scanned using six OCT systems. Imaging system and probe performance were quantitatively assessed for signal penetration, layer differentiation, and epithelium (EP) measurement. Fitted exponential decay curves with corresponding α constant and intensity thresholding segmentation were utilized to quantify the aforementioned parameters. RESULTS The smallest average α constant and deepest signal penetration was of the SS-OCT 1700 nm 90 kHz microscope system (α = -1.74), followed by the SS-OCT 1310 nm 200 kHz VCSEL microscope system (α = -1.99), and SS-OCT 1310 nm 50 kHz rigid forward viewing endoscope system (α = -2.23). The EP was not readily visualized for three out of six systems, but was detected using automated segmentation. Average EP thickness (mean ± SD) was calculated as 55.79 ± 31.86 μm which agrees favorably with previous literature. CONCLUSION Comparisons of OCT systems are challenging, as they encompass different probe design, optical path, and lasers, depending on application. Practical evaluation of different systems using computer based quantitative image processing and segmentation revealed basic, constructive information, such as EP measurements. To further validate the comparisons of system performance with clinical usability, in vivo human laryngeal imaging will be conducted. Further development of automated image processing and segmentation can be useful in rapid analysis of information. Lasers Surg. Med. 51:412-422, 2019. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Tiffany T. Pham
- Beckman Laser Institute & Medical Clinic, University of California—Irvine, Irvine, California 92612
- School of Medicine, University of California—Irvine, Irvine, California 92617
| | - Lily Chen
- Beckman Laser Institute & Medical Clinic, University of California—Irvine, Irvine, California 92612
| | - Andrew E. Heidari
- Beckman Laser Institute & Medical Clinic, University of California—Irvine, Irvine, California 92612
- Department of Biomedical Engineering, University of California—Irvine, Irvine, California 92697
| | - Jason J. Chen
- Beckman Laser Institute & Medical Clinic, University of California—Irvine, Irvine, California 92612
- Department of Biomedical Engineering, University of California—Irvine, Irvine, California 92697
| | - Alisa Zhukhovitskaya
- Beckman Laser Institute & Medical Clinic, University of California—Irvine, Irvine, California 92612
- Department of Otolaryngology—Head and Neck Surgery, University of California—Irvine, Orange, California 92868
| | - Yan Li
- Beckman Laser Institute & Medical Clinic, University of California—Irvine, Irvine, California 92612
- Department of Biomedical Engineering, University of California—Irvine, Irvine, California 92697
| | - Urja Patel
- Beckman Laser Institute & Medical Clinic, University of California—Irvine, Irvine, California 92612
| | - Zhongping Chen
- Beckman Laser Institute & Medical Clinic, University of California—Irvine, Irvine, California 92612
- Department of Biomedical Engineering, University of California—Irvine, Irvine, California 92697
| | - Brian J.F. Wong
- Beckman Laser Institute & Medical Clinic, University of California—Irvine, Irvine, California 92612
- School of Medicine, University of California—Irvine, Irvine, California 92617
- Department of Biomedical Engineering, University of California—Irvine, Irvine, California 92697
- Department of Otolaryngology—Head and Neck Surgery, University of California—Irvine, Orange, California 92868
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Yamanaka M, Hayakawa N, Nishizawa N. High-spatial-resolution deep tissue imaging with spectral-domain optical coherence microscopy in the 1700-nm spectral band. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-4. [PMID: 31364330 PMCID: PMC6995893 DOI: 10.1117/1.jbo.24.7.070502] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 07/10/2019] [Indexed: 05/25/2023]
Abstract
We present three-dimensional (3-D) high-resolution spectral-domain optical coherence microscopy (SD-OCM) by using a supercontinuum (SC) fiber laser source with 300-nm spectral bandwidth (full-width at half-maximum) in the 1700-nm spectral band. By using low-coherence interferometry with SC light and a confocal detection scheme, we realized lateral and axial resolutions of 3.4 and 3.8 μm in tissue (n = 1.38), respectively. This is, to the best of our knowledge, the highest 3-D spatial resolution reported among those of Fourier-domain optical coherence imaging techniques in the 1700-nm spectral band. In our SD-OCM, to enhance the imaging depth, a full-range method was implemented, which suppressed the formation of a coherent ghost image and allowed us to set the zero-delay position inside the samples. We demonstrated the 3-D high-resolution imaging capability of 1700-nm SD-OCM through the measurement of an interference signal from a mirror surface and imaging of a single 200-nm polystyrene bead and a pig thyroid gland. Deep tissue imaging at a depth of up to 1.8 mm was also demonstrated. This is the first demonstration of 3-D high-resolution SD-OCM in the 1700-nm spectral band.
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Affiliation(s)
| | - Naoki Hayakawa
- Nagoya University, Department of Electronics, Nagoya, Aichi, Japan
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Saini TS, Trung Hoa NP, Tuan TH, Luo X, Suzuki T, Ohishi Y. Tapered tellurite step-index optical fiber for coherent near-to-mid-IR supercontinuum generation: experiment and modeling. APPLIED OPTICS 2019; 58:415-421. [PMID: 30645322 DOI: 10.1364/ao.58.000415] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 12/10/2018] [Indexed: 06/09/2023]
Abstract
We demonstrate broadband highly coherent near-to-mid-IR supercontinuum generation using a short length of tapered tellurite step-index fiber pumped with an ultrafast laser in normal dispersion regime. The tapered tellurite fiber possesses all-normal dispersion characteristics within the whole range of the generated supercontinuum spectrum. A highly coherent near-to-mid-IR supercontinuum spectrum spanning 1.28 to 3.31 μm at a -40 dB intensity level is obtained using a 3.2 cm long tapered tellurite fiber when it is pumped with a 200 fs laser pulse with a peak power of 19.8 kW at 2 μm. To obtain the supercontinuum spectrum, we also carried out numerical modeling for the tapered tellurite step-index fiber with the same geometrical parameters and pump conditions used in the experiment. The numerical observation supports the experimentally obtained result. The findings of this work show that the fabricated tapered tellurite step-index fiber is a promising nonlinear medium to obtain a coherent near-to-mid-IR supercontinuum spectrum in a short length of the fiber.
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Choudhury V, Arun S, Prakash R, Supradeepa VR. High-power continuous-wave supercontinuum generation in highly nonlinear fibers pumped with high-order cascaded Raman fiber amplifiers. APPLIED OPTICS 2018; 57:5978-5982. [PMID: 30118022 DOI: 10.1364/ao.57.005978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 06/20/2018] [Indexed: 06/08/2023]
Abstract
A novel method for efficient generation of a high-power, equalized continuous-wave supercontinuum source in an all-conventional silica fiber architecture is demonstrated. Highly nonlinear fiber is pumped in its anomalous dispersion region using a novel, high-power, L-band laser. The L-band laser encompasses a sixth-order cascaded Raman amplifier which is pumped with a high-power Ytterbium-doped fiber laser and amplifies a low-power, tunable L-band seed source. The supercontinuum generated 35 W of power with ∼40% efficiency. The supercontinuum spectrum was measured to have a high degree of flatness of better than 5 dB over 400 nm of bandwidth (1.3-1.7 μm, limited by spectrum analyzer range) and a power spectral density in this region of >50 mW/nm. The extent of the SC spectrum is estimated to be up to 2 μm.
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Harper DJ, Augustin M, Lichtenegger A, Eugui P, Reyes C, Glösmann M, Hitzenberger CK, Baumann B. White light polarization sensitive optical coherence tomography for sub-micron axial resolution and spectroscopic contrast in the murine retina. BIOMEDICAL OPTICS EXPRESS 2018; 9:2115-2129. [PMID: 29760974 PMCID: PMC5946775 DOI: 10.1364/boe.9.002115] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 03/29/2018] [Accepted: 03/30/2018] [Indexed: 05/03/2023]
Abstract
A white light polarization sensitive optical coherence tomography system has been developed, using a supercontinuum laser as the light source. By detecting backscattered light from 400 - 700 nm, an axial resolution of 1.0 µm in air was achieved. The system consists of a free-space interferometer and two homemade spectrometers that detect orthogonal polarization states. Following system specifications, images of a healthy murine retina as acquired by this non-contact system are presented, showing high resolution reflectivity images as well as spectroscopic and polarization sensitive contrast. Additional images of the very-low-density-lipoprotein-receptor (VLDLR) knockout mouse model were acquired. The high resolution allows the detection of small lesions in the retina.
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Affiliation(s)
- Danielle J. Harper
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Marco Augustin
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Antonia Lichtenegger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Pablo Eugui
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Carlos Reyes
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Martin Glösmann
- University of Veterinary Medicine Vienna, Core Facility for Research and Technology, Veterinaerplatz 1, 1210 Vienna,
Austria
| | - Christoph K. Hitzenberger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Bernhard Baumann
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
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Wang N, Cai JH, Qi X, Chen SP, Yang LJ, Hou J. Ultraviolet-enhanced supercontinuum generation with a mode-locked Yb-doped fiber laser operating in dissipative-soliton-resonance region. OPTICS EXPRESS 2018; 26:1689-1696. [PMID: 29402040 DOI: 10.1364/oe.26.001689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 01/09/2018] [Indexed: 06/07/2023]
Abstract
We experimentally demonstrate an all-fiber, ultraviolet-enhanced, supercontinuum generation in a specifically designed seven-core photonic crystal fiber pumped by a picosecond Yb-doped master oscillator power amplifier (MOPA). The MOPA source is seeded by a giant-chirped Yb-doped mode-locked fiber laser operating in the dissipative-soliton-resonance (DSR) region. The DSR is achieved by using a nonlinear optical loop mirror (NOLM) with a fundamental repetition rate of 4.5 MHz and a central wavelength of 1035 nm. An extremely wide optical spectrum spanning from 350 nm to 2400 nm is obtained with a total output power of 6.86 W.
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Emami SD, Dashtabi MM, Lee HJ, Arabanian AS, Rashid HAA. 1700 nm and 1800 nm band tunable thulium doped mode-locked fiber lasers. Sci Rep 2017; 7:12747. [PMID: 28986584 PMCID: PMC5630590 DOI: 10.1038/s41598-017-13200-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 09/19/2017] [Indexed: 11/25/2022] Open
Abstract
This paper presents short wavelength operation of tunable thulium-doped mode-locked lasers with sweep ranges of 1702 to 1764 nm and 1788 to 1831 nm. This operation is realized by a combination of the partial amplified spontaneous emission suppression method, the bidirectional pumping mechanism and the nonlinear polarization rotation (NPR) technique. Lasing at emission bands lower than the 1800 nm wavelength in thulium-doped fiber lasers is achieved using mode confinement loss in a specially designed photonic crystal fiber (PCF). The enlargement of the first outer ring air holes around the core region of the PCF attenuates emissions above the cut-off wavelength and dominates the active region. This amplified spontaneous emission (ASE) suppression using our presented PCF is applied to a mode-locked laser cavity and is demonstrated to be a simple and compact solution to widely tunable all-fiber lasers.
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Affiliation(s)
- Siamak Dawazdah Emami
- Faculty of Engineering, Multimedia University, 63100, Cyberjaya, Selangor, Malaysia. .,Laser and Plasma Research Institute, Shahid Beheshti University, Evin, Tehran, Iran.
| | | | - Hui Jing Lee
- Photonics Technology Research Group, Universiti Tenaga Nasional, 43000, Kajang, Selangor, Malaysia
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Chung HY, Liu W, Cao Q, Kärtner FX, Chang G. Er-fiber laser enabled, energy scalable femtosecond source tunable from 1.3 to 1.7 µm. OPTICS EXPRESS 2017; 25:15760-15771. [PMID: 28789088 DOI: 10.1364/oe.25.015760] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 05/23/2017] [Indexed: 05/23/2023]
Abstract
We demonstrate that energetic femtosecond pulses tunable from 1.3 to 1.7 µm can be achieved using self-phase modulation enabled spectral broadening followed by spectral lobe filtering. Based on a home-built 5-W Er-fiber laser system operating at 31-MHz repetition rate, we obtain femtosecond pulses that can be continuously tuned from 1.3 to 1.7 µm with >4.5 nJ pulse energy. We further optimize the spectral broadening process using a fiber with larger mode area and scale up the pulse energy to >10 nJ; the resulting pulse duration is as short as ~50 fs. Such a widely tunable, energetic femtosecond source is well suited for driving a laser scanning microscope to perform deep tissue multiphoton microscopy.
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Klimczak M, Siwicki B, Zhou B, Bache M, Pysz D, Bang O, Buczyński R. Coherent supercontinuum bandwidth limitations under femtosecond pumping at 2 µm in all-solid soft glass photonic crystal fibers. OPTICS EXPRESS 2016; 24:29406-29416. [PMID: 28059327 DOI: 10.1364/oe.24.029406] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Two all-solid glass photonic crystal fibers with all-normal dispersion profiles are evaluated for coherent supercontinuum generation under pumping in the 2.0 μm range. In-house boron-silicate and commercial lead-silicate glasses were used to fabricate fibers optimized for either flat dispersion, albeit with lower nonlinearity, or with larger dispersion profile curvature but with much higher nonlinearity. Recorded spectra at the redshifted edge reached 2500-2800 nm depending on fiber type. Possible factors behind these differences are discussed with numerical simulations. The fiber enabling the broadest spectrum is suggested as an efficient first stage of an all-normal dispersion cascade for coherent supercontinuum generation exceeding 3000 nm.
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Yamanaka M, Teranishi T, Kawagoe H, Nishizawa N. Optical coherence microscopy in 1700 nm spectral band for high-resolution label-free deep-tissue imaging. Sci Rep 2016; 6:31715. [PMID: 27546517 PMCID: PMC4992836 DOI: 10.1038/srep31715] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 07/25/2016] [Indexed: 01/10/2023] Open
Abstract
Optical coherence microscopy (OCM) is a label-free, high-resolution, three-dimensional (3D) imaging technique based on optical coherence tomography (OCT) and confocal microscopy. Here, we report that the 1700-nm spectral band has the great potential to improve the imaging depth in high-resolution OCM imaging of animal tissues. Recent studies to improve the imaging depth in OCT revealed that the 1700-nm spectral band is a promising choice for imaging turbid scattering tissues due to the low attenuation of light in the wavelength region. In this study, we developed high-resolution OCM by using a high-power supercontinuum source in the 1700-nm spectral band, and compared the attenuation of signal-to-noise ratio between the 1700-nm and 1300-nm OCM imaging of a mouse brain under the condition of the same sensitivity. The comparison clearly showed that the 1700-nm OCM provides larger imaging depth than the 1300-nm OCM. In this 1700-nm OCM, the lateral resolution of 1.3 μm and the axial resolution of 2.8 μm, when a refractive index was assumed to be 1.38, was achieved.
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Affiliation(s)
- Masahito Yamanaka
- Department of Quantum Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8603, Japan
| | - Tatsuhiro Teranishi
- Department of Quantum Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8603, Japan
| | - Hiroyuki Kawagoe
- Department of Quantum Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8603, Japan
| | - Norihiko Nishizawa
- Department of Quantum Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8603, Japan
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Noronen T, Okhotnikov O, Gumenyuk R. Electronically tunable thulium-holmium mode-locked fiber laser for the 1700-1800 nm wavelength band. OPTICS EXPRESS 2016; 24:14703-8. [PMID: 27410623 DOI: 10.1364/oe.24.014703] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We demonstrate a widely tunable, mode-locked fiber laser capable of producing sub-picosecond pulses between 1705 and 1805 nm. The 100 nm tuning range is achieved by using intracavity acousto-optic tunable filter. The laser delivers highly stable pulses via self-starting hybrid mode-locking triggered by frequency-shifting and nonlinear polarization evolution.
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26
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Noronen T, Firstov S, Dianov E, Okhotnikov OG. 1700 nm dispersion managed mode-locked bismuth fiber laser. Sci Rep 2016; 6:24876. [PMID: 27097798 PMCID: PMC4838940 DOI: 10.1038/srep24876] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 04/06/2016] [Indexed: 11/30/2022] Open
Abstract
We demonstrate the first 1.7 μm bismuth-doped fiber laser generating ultrashort pulses via passive mode-locking. Pulse operation has been achieved for both anomalous and normal dispersion of the laser cavity owing to broadband characteristics of carbon nanotube saturable absorber. The laser delivered 1.65 ps pulses in net anomalous dispersion regime. In normal dispersion regime, the laser delivered 14 ps pulses which could be compressed to 1.2 ps using external fiber compressor.
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Affiliation(s)
- Teppo Noronen
- Optoelectronics Research Centre, Tampere University of Technology, Korkeakoulunkatu 3, 33720 Tampere, Finland
| | - Sergei Firstov
- Fiber Optics Research Center, Russian Academy of Sciences, 38 Vavilov Street, 119333 Moscow, Russia
| | - Evgeny Dianov
- Fiber Optics Research Center, Russian Academy of Sciences, 38 Vavilov Street, 119333 Moscow, Russia
| | - Oleg G Okhotnikov
- Optoelectronics Research Centre, Tampere University of Technology, Korkeakoulunkatu 3, 33720 Tampere, Finland.,Ulyanovsk State University, L. Tolstoy str. 42, 432017 Ulyanovsk, Russia
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27
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Chu KC, Jiang HY, Yang SD. High-energy femtosecond amplifier-similariton Er-doped fiber oscillator. OPTICS LETTERS 2015; 40:5319-5322. [PMID: 26565864 DOI: 10.1364/ol.40.005319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We demonstrated high-energy femtosecond amplifier-similariton oscillators with predominant Er-doped fibers of normal dispersion. Stably mode-locked pulses of ~3 ps, 33 nJ were produced at 720 mW pump power, while a double-pass grating pair of 36% efficiency compressed the pulses to 156 fs and 47 kW peak power (a new record). Broad mode-locked spectra supporting transform-limited pulsewidths down to 60 fs were obtained by adjusting the intracavity waveplates and filter. Continuous wave (CW) mode-locked pulses up to 53 nJ were generated by increasing the pump power to 1.5 W and by introducing significant spectral phase modulation via an intracavity pulse shaper. However, weak subpulses or pedestal could arise along with increased shot-to-shot fluctuation under this extreme operation mode.
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28
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Dynamics of a Dispersion-Managed Passively Mode-Locked Er-Doped Fiber Laser Using Single Wall Carbon Nanotubes. PHOTONICS 2015. [DOI: 10.3390/photonics2030808] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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29
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Tanaka M, Hirano M, Murashima K, Obi H, Yamaguchi R, Hasegawa T. 1.7-μm spectroscopic spectral-domain optical coherence tomography for imaging lipid distribution within blood vessel. OPTICS EXPRESS 2015; 23:6645-55. [PMID: 25836881 DOI: 10.1364/oe.23.006645] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We have developed a spectroscopic optical coherence tomography (OCT) for imaging lipid distribution within blood vessel in order to detect coronary artery plaque. A 1.7-μm spectral-domain OCT with A-scan rate of 47 kHz is fabricated using a broadband light source based on super-luminescent diodes and spectrometers based on extended InGaAs line sensors. We demonstrate imaging of lipid distribution in an in vitro artery model with lipid. The sensitivity and specificity in the differentiation between artery and lipid are 87% and 90% in the training, respectively. The validation test also shows detection of lipid with an accuracy over 90%.
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Cheung CS, Daniel JMO, Tokurakawa M, Clarkson WA, Liang H. High resolution Fourier domain optical coherence tomography in the 2 μm wavelength range using a broadband supercontinuum source. OPTICS EXPRESS 2015; 23:1992-2001. [PMID: 25836070 DOI: 10.1364/oe.23.001992] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
A 220 nm bandwidth supercontinuum source in the two-micron wavelength range has been developed for use in a Fourier domain optical coherence tomography (FDOCT) system. This long wavelength source serves to enhance probing depth in highly scattering material with low water content. We present results confirming improved penetration depth in high opacity paint samples while achieving the high axial resolution needed to resolve individual paint layers. This is the first FDOCT developed in the 2 μm wavelength regime that allows fast, efficient capturing of 3D image cubes at a high axial resolution of 13 μm in air (or 9 μm in paint).
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