1
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Jiao L, Wang C, Wang J, Yang Z. Corneal damage threshold induced by supercontinuum source: A further study. Lasers Surg Med 2023; 55:846-852. [PMID: 37655759 DOI: 10.1002/lsm.23722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 07/27/2023] [Accepted: 08/20/2023] [Indexed: 09/02/2023]
Abstract
OBJECTIVES Previous report shows that corneal spot size is an important influence factor on damage threshold induced by supercontinumm (SC) source. However, damage thresholds were determined for the spot size of only 0.37 mm due to the low output of the employed SC source at that time. The objectives of this study are to determine the lowest possible corneal damage threshold at a large corneal spot size using a more powerful SC source and provide data for the future possible refinements of laser safety standards. MATERIALS AND METHODS A series of experiments was conducted in the New Zealand white rabbit model to determine the corneal damage threshold induced by a 900-2000 nm SC source, with corneal 1/e beam diameter of about 1.2 mm. Slit-lamp biomicroscope was employed to reveal the corneal damage characteristics. By employing the action spectra determined through the analysis of current laser safety guidelines and standards, the effective damage threshold could be calculated. RESULTS The determined damage threshold given in terms of the peak radiant exposure for the exposure duration of 0.14 s was 44.3 J/cm2 . At threshold level, corneal damages involved the epithelium and the shallower stroma. The safety factor between the effective damage threshold and the corresponding maximum permissible exposure (MPE) was about 45. CONCLUSIONS Present corneal MPEs in the wavelength range of 700-1200 nm may be conservative and corneal damage thresholds for the infrared A wavelengths should be determined in future studies.
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Affiliation(s)
- Luguang Jiao
- Beijing Institute of Radiation Medicine, Beijing, People's Republic of China
| | - Chao Wang
- Beijing Institute of Radiation Medicine, Beijing, People's Republic of China
| | - Jiarui Wang
- Beijing Institute of Radiation Medicine, Beijing, People's Republic of China
| | - Zaifu Yang
- Beijing Institute of Radiation Medicine, Beijing, People's Republic of China
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2
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Castelló-Lurbe D. Breaking fundamental noise limitations to supercontinuum generation. OPTICS LETTERS 2022; 47:1299-1302. [PMID: 35290298 DOI: 10.1364/ol.452104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 01/31/2022] [Indexed: 06/14/2023]
Abstract
Supercontinuum generation in the anomalous group-velocity dispersion regime is widely considered to be inherently unstable against input pulse fluctuations. This constraint has compelled a coherent supercontinuum to be triggered by femtosecond pulses. In this work, conditions for breaking this fundamental limitation are analytically derived and realized in a silicon waveguide by exploiting the Kerr nonlinearity dispersion. On this basis, coherent supercontinuum generation with picosecond pulses and anomalous group-velocity dispersion is numerically demonstrated, which crosses a long-standing frontier in nonlinear optics.
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3
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Ji X, Mojahed D, Okawachi Y, Gaeta AL, Hendon CP, Lipson M. Millimeter-scale chip-based supercontinuum generation for optical coherence tomography. SCIENCE ADVANCES 2021; 7:eabg8869. [PMID: 34533990 PMCID: PMC8448444 DOI: 10.1126/sciadv.abg8869] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Supercontinuum sources for optical coherence tomography (OCT) have raised great interest as they provide broad bandwidth to enable high resolution and high power to improve imaging sensitivity. Commercial fiber-based supercontinuum systems require high pump powers to generate broad bandwidth and customized optical filters to shape/attenuate the spectra. They also have limited sensitivity and depth performance. We introduce a supercontinuum platform based on a 1-mm2 Si3N4 photonic chip for OCT. We directly pump and efficiently generate supercontinuum near 1300 nm without any postfiltering. With a 25-pJ pump pulse, we generate a broadband spectrum with a flat 3-dB bandwidth of 105 nm. Integrating the chip into a spectral domain OCT system, we achieve 105-dB sensitivity and 1.81-mm 6-dB sensitivity roll-off with 300-μW optical power on sample. We image breast tissue to demonstrate strong imaging performance. Our chip will pave the way toward portable OCT and incorporating integrated photonics into optical imaging technologies.
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Affiliation(s)
- Xingchen Ji
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
| | - Diana Mojahed
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Yoshitomo Okawachi
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, USA
| | - Alexander L. Gaeta
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, USA
| | - Christine P. Hendon
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
- Corresponding author. (M.L.); (C.P.H.)
| | - Michal Lipson
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
- Corresponding author. (M.L.); (C.P.H.)
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4
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Shang H, Zhang M, Sun D, Liu YG, Wang Z. Optical characterization of Ge 11.5As 24S 64.5 glass for an on-chip supercontinuum. APPLIED OPTICS 2021; 60:5451-5455. [PMID: 34263785 DOI: 10.1364/ao.426456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/02/2021] [Indexed: 06/13/2023]
Abstract
An on-chip supercontinuum (SC) source spanning from 900 nm to 2000 nm has been experimentally presented and analyzed based on a Ge11.5As24S64.5 (GeAsS) planar waveguide at telecommunication wavelength. The nonlinear response parameter (γ) of the GeAsS waveguide is estimated to be ∼12/W/m at the pump wavelength using resonant grating waveguide (RGW) nonlinear refractive index (n2=2×10-18m2/W), which is measured by the z-scan technique. The dispersion of the waveguide is carefully engineered based on the refractive index of the GeAsS film where the film structure is confirmed by a Raman spectrum exhibiting consistency with the corresponding glass. The results suggest that the GeAsS glass is expected to be an ideal platform for on-chip devices.
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5
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Montesinos-Ballester M, Lafforgue C, Frigerio J, Ballabio A, Vakarin V, Liu Q, Ramirez JM, Roux XL, Bouville D, Barzaghi A, Alonso-Ramos C, Vivien L, Isella G, Marris-Morini D. On-Chip Mid-Infrared Supercontinuum Generation from 3 to 13 μm Wavelength. ACS PHOTONICS 2020; 7:3423-3429. [PMID: 33365361 PMCID: PMC7747866 DOI: 10.1021/acsphotonics.0c01232] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Indexed: 05/14/2023]
Abstract
Midinfrared spectroscopy is a universal way to identify chemical and biological substances. Indeed, when interacting with a light beam, most molecules are responsible for absorption at specific wavelengths in the mid-IR spectrum, allowing to detect and quantify small traces of substances. On-chip broadband light sources in the mid-infrared are thus of significant interest for compact sensing devices. In that regard, supercontinuum generation offers a mean to efficiently perform coherent light conversion over an ultrawide spectral range, in a single and compact device. This work reports the experimental demonstration of on-chip two-octave supercontinuum generation in the mid-infrared wavelength, ranging from 3 to 13 μm (that is larger than 2500 cm-1) and covering almost the full transparency window of germanium. Such an ultrawide spectrum is achieved thanks to the unique features of Ge-rich graded SiGe waveguides, which allow second-order dispersion tailoring and low propagation losses over a wide wavelength range. The influence of the pump wavelength and power on the supercontinuum spectra has been studied. A good agreement between the numerical simulations and the experimental results is reported. Furthermore, a very high coherence is predicted in the entire spectrum. These results pave the way for wideband, coherent, and compact mid-infrared light sources by using a single device and compatible with large-scale fabrication processes.
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Affiliation(s)
- Miguel Montesinos-Ballester
- Centre
de Nanosciences et de Nanotechnologies, Université Paris-Saclay, CNRS, 91120 Palaiseau, France
- E-mail:
| | - Christian Lafforgue
- Centre
de Nanosciences et de Nanotechnologies, Université Paris-Saclay, CNRS, 91120 Palaiseau, France
| | - Jacopo Frigerio
- L-NESS,
Dipartimento di Fisica, Politecnico di Milano,
Polo di Como, Via Anzani 42, 22100 Como, Italy
| | - Andrea Ballabio
- L-NESS,
Dipartimento di Fisica, Politecnico di Milano,
Polo di Como, Via Anzani 42, 22100 Como, Italy
| | - Vladyslav Vakarin
- Centre
de Nanosciences et de Nanotechnologies, Université Paris-Saclay, CNRS, 91120 Palaiseau, France
| | - Qiankun Liu
- Centre
de Nanosciences et de Nanotechnologies, Université Paris-Saclay, CNRS, 91120 Palaiseau, France
| | - Joan Manel Ramirez
- Centre
de Nanosciences et de Nanotechnologies, Université Paris-Saclay, CNRS, 91120 Palaiseau, France
| | - Xavier Le Roux
- Centre
de Nanosciences et de Nanotechnologies, Université Paris-Saclay, CNRS, 91120 Palaiseau, France
| | - David Bouville
- Centre
de Nanosciences et de Nanotechnologies, Université Paris-Saclay, CNRS, 91120 Palaiseau, France
| | - Andrea Barzaghi
- L-NESS,
Dipartimento di Fisica, Politecnico di Milano,
Polo di Como, Via Anzani 42, 22100 Como, Italy
| | - Carlos Alonso-Ramos
- Centre
de Nanosciences et de Nanotechnologies, Université Paris-Saclay, CNRS, 91120 Palaiseau, France
| | - Laurent Vivien
- Centre
de Nanosciences et de Nanotechnologies, Université Paris-Saclay, CNRS, 91120 Palaiseau, France
| | - Giovanni Isella
- L-NESS,
Dipartimento di Fisica, Politecnico di Milano,
Polo di Como, Via Anzani 42, 22100 Como, Italy
| | - Delphine Marris-Morini
- Centre
de Nanosciences et de Nanotechnologies, Université Paris-Saclay, CNRS, 91120 Palaiseau, France
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6
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Sinobad M, DellaTorre A, Armand R, Luther-Davies B, Ma P, Madden S, Mitchell A, Moss DJ, Hartmann JM, Fedeli JM, Monat C, Grillet C. Mid-infrared supercontinuum generation in silicon-germanium all-normal dispersion waveguides. OPTICS LETTERS 2020; 45:5008-5011. [PMID: 32932439 DOI: 10.1364/ol.402159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 08/01/2020] [Indexed: 05/27/2023]
Abstract
We demonstrate coherent supercontinuum generation spanning over an octave from a silicon germanium-on-silicon waveguide using ∼200fs pulses at a wavelength of 4 µm. The waveguide is engineered to provide low all-normal dispersion in the TM polarization. We validate the coherence of the generated supercontinuum via simulations, with a high degree of coherence across the entire spectrum. Such a generated supercontinuum could lend itself to pulse compression down to 22 fs.
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7
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Kuyken B, Billet M, Leo F, Yvind K, Pu M. Octave-spanning coherent supercontinuum generation in an AlGaAs-on-insulator waveguide. OPTICS LETTERS 2020; 45:603-606. [PMID: 32004262 DOI: 10.1364/ol.45.000603] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 11/21/2019] [Indexed: 06/10/2023]
Abstract
We demonstrate supercontinuum generation over an octave spaning from 1055 to 2155 nm on the highly nonlinear aluminum gallium arsenide (AlGaAs)-on-insulator platform. This is enabled by the generation of two dispersive waves in a 3-mm-long dispersion-engineered nano-waveguide. The waveguide is pumped at telecom wavelengths (1555 nm) with 3.6 pJ femtosecond pulses. We experimentally validate the coherence of the generated supercontinuum around the pump wavelength (1450-1750 nm), and our numerical simulation shows a high degree of coherence over the full spectrum.
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8
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Ren H, Shen L, Runge AFJ, Hawkins TW, Ballato J, Gibson U, Peacock AC. Low-loss silicon core fibre platform for mid-infrared nonlinear photonics. LIGHT, SCIENCE & APPLICATIONS 2019; 8:105. [PMID: 31798844 PMCID: PMC6872570 DOI: 10.1038/s41377-019-0217-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 10/22/2019] [Accepted: 11/01/2019] [Indexed: 06/10/2023]
Abstract
Broadband mid-infrared light sources are highly desired for wide-ranging applications that span free-space communications to spectroscopy. In recent years, silicon has attracted great interest as a platform for nonlinear optical wavelength conversion in this region, owing to its low losses (linear and nonlinear) and high stability. However, most research in this area has made use of small core waveguides fabricated from silicon-on-insulator platforms, which suffer from high absorption losses of the use of silica cladding, limiting their ability to generate light beyond 3 µm. Here, we design and demonstrate a compact silicon core, silica-clad waveguide platform that has low losses across the entire silicon transparency window. The waveguides are fabricated from a silicon core fibre that is tapered to engineer mode properties to ensure efficient nonlinear propagation in the core with minimal interaction of the mid-infrared light with the cladding. These waveguides exhibit many of the benefits of fibre platforms, such as a high coupling efficiency and power handling capability, allowing for the generation of mid-infrared supercontinuum spectra with high brightness and coherence spanning almost two octaves (1.6-5.3 µm).
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Affiliation(s)
- Haonan Ren
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ UK
| | - Li Shen
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ UK
- Wuhan National Laboratory for Optoelectronics (WNLO), Huazhong University of Science and Technology, 430074 Wuhan, China
| | - Antoine F. J. Runge
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ UK
- Present Address: The Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, Sydney, NSW 2006 Australia
| | - Thomas W. Hawkins
- Department of Materials Science and Engineering, Clemson University, Clemson, SC 29634 USA
| | - John Ballato
- Department of Materials Science and Engineering, Clemson University, Clemson, SC 29634 USA
| | - Ursula Gibson
- Department of Physics, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway
- Department of Applied Physics, KTH Royal Institute of Technology, 10044 Stockholm, Sweden
| | - Anna C. Peacock
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ UK
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9
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Jiao L, Fan Y, Wang J, Yang Z. Corneal Damage Effects Induced by a 770-2,500 nm Supercontinuum Light Source. Lasers Surg Med 2019; 52:560-568. [PMID: 31713256 DOI: 10.1002/lsm.23182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/28/2019] [Indexed: 11/12/2022]
Abstract
BACKGROUND AND OBJECTIVES Widespread applications of supercontinuum (SC) source lead to the possibility of ocular damages. However, the corneal damage effects induced by SC have not been explored before. The objectives of this study are to determine the rabbit corneal injury threshold for SC radiation and to examine whether the existing safety guidelines and standards are suitable for the hazard evaluation of this new kind of light source. STUDY DESIGN/MATERIALS AND METHODS A series of experiments was conducted in the New Zealand white rabbit model to determine the corneal damage thresholds induced by a 770-2,500 nm SC source, with a corneal 1/e beam diameter of 0.37 mm. Through slit-lamp biomicroscope, optical coherence tomography (OCT), and histopathology the corneal damage characteristics at the threshold level were revealed. By employing the action spectra determined through the analysis of safety guidelines and standards, the damage thresholds for SC source could be compared with the corresponding exposure limits. RESULTS The determined damage thresholds given in terms of the peak radiant exposure for exposure durations of 2.0 and 10.0 seconds were 2.1 × 103 and 7.4 × 103 J/cm2 , respectively. At threshold level, corneal damages involved the epithelium and the shallower stroma, and no obvious changes could be found in the deep stroma, Descemet's membrane, and endothelium. CONCLUSIONS The exposure limits for the anterior parts of the eye in the wavelength range of 700-1,200 nm are overly conservative. The obtained results contribute to the knowledge base for the hazard evaluation of SC source. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Luguang Jiao
- Beijing Institute of Radiation Medicine, Beijing, People's Republic of China
| | - Yan Fan
- Beijing Institute of Radiation Medicine, Beijing, People's Republic of China
| | - Jiarui Wang
- Beijing Institute of Radiation Medicine, Beijing, People's Republic of China
| | - Zaifu Yang
- Beijing Institute of Radiation Medicine, Beijing, People's Republic of China
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10
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Shams-Ansari A, Latawiec P, Okawachi Y, Venkataraman V, Yu M, Desiatov B, Atikian H, Harris GL, Picqué N, Gaeta AL, Lončar M. Supercontinuum generation in angle-etched diamond waveguides. OPTICS LETTERS 2019; 44:4056-4059. [PMID: 31415546 DOI: 10.1364/ol.44.004056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 07/16/2019] [Indexed: 06/10/2023]
Abstract
We experimentally demonstrate on-chip supercontinuum generation in the visible region in angle-etched diamond waveguides. We measure an output spectrum spanning 670-920 nm in a 5-mm-long waveguide using 100-fs pulses with 187 pJ of incident pulse energy. Our fabrication technique, combined with diamond's broad transparency window, offers a potential route toward broadband supercontinuum generation in the UV domain.
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11
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Jiao L, Fan Y, Wang J, Yang Z. Comparative study of retinal injuries induced by a 420-750 nm supercontinuum source and a 532 nm laser. BIOMEDICAL OPTICS EXPRESS 2019; 10:3018-3029. [PMID: 31259071 PMCID: PMC6583330 DOI: 10.1364/boe.10.003018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 05/20/2019] [Accepted: 05/20/2019] [Indexed: 06/09/2023]
Abstract
With the rapid developments and widespread applications of supercontinuum (SC) sources, ocular damage induced by this new light source becomes possible and receives our concern. To explore the ocular damage effect of an SC source, a series of experiments were conducted in a chinchilla grey rabbit model to determine the in-vivo retinal damage thresholds induced by a 420-750 nm SC source and a 532 nm laser. For the SC source, the beam divergence and the corneal 1/e2 beam diameter were 3.8 mrad and 2.45 mm, respectively. The determined ED50 values given in terms of total intraocular energy (TIE) for exposure durations of 0.1, 1.0, and 10.0 s were 1.57, 12.1, and 86.0 mJ, respectively. For the 532 nm laser, the beam divergence and the corneal 1/e2 beam diameter were 0.9 mrad and 2.25 mm, respectively. The determined ED50 value for an exposure duration of 0.1 s was 1.39 mJ. By employing the retinal thermal action spectrum in the ICNIRP guidelines, the damage thresholds for SC sources could be compared with the exposure limits for incoherent and laser radiation. Between the 420-750 nm SC source and the 532 nm laser, no significant difference could be found for the damage effects including damage threshold, retinal lesion size, and histological damage characteristics.
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Affiliation(s)
- Luguang Jiao
- Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Yan Fan
- Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Jiarui Wang
- Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Zaifu Yang
- Beijing Institute of Radiation Medicine, Beijing 100850, China
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12
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Physical origin of higher-order soliton fission in nanophotonic semiconductor waveguides. Sci Rep 2018; 8:17177. [PMID: 30464320 PMCID: PMC6249288 DOI: 10.1038/s41598-018-34344-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 10/09/2018] [Indexed: 11/23/2022] Open
Abstract
Supercontinuum generation in Kerr media has become a staple of nonlinear optics. It has been celebrated for advancing the understanding of soliton propagation as well as its many applications in a broad range of fields. Coherent spectral broadening of laser light is now commonly performed in laboratories and used in commercial “white light” sources. The prospect of miniaturizing the technology is currently driving experiments in different integrated platforms such as semiconductor on insulator waveguides. Central to the spectral broadening is the concept of higher-order soliton fission. While widely accepted in silica fibers, the dynamics of soliton decay in semiconductor waveguides is yet poorly understood. In particular, the role of nonlinear loss and free carriers, absent in silica, remains an open question. Here, through experiments and simulations, we show that nonlinear loss is the dominant perturbation in wire waveguides, while free-carrier dispersion is dominant in photonic crystal waveguides.
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13
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Singh N, Xin M, Vermeulen D, Shtyrkova K, Li N, Callahan PT, Magden ES, Ruocco A, Fahrenkopf N, Baiocco C, Kuo BPP, Radic S, Ippen E, Kärtner FX, Watts MR. Octave-spanning coherent supercontinuum generation in silicon on insulator from 1.06 μm to beyond 2.4 μm. LIGHT, SCIENCE & APPLICATIONS 2018; 7:17131. [PMID: 30839639 PMCID: PMC6107049 DOI: 10.1038/lsa.2017.131] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 08/31/2017] [Accepted: 09/01/2017] [Indexed: 05/19/2023]
Abstract
Efficient complementary metal-oxide semiconductor-based nonlinear optical devices in the near-infrared are in strong demand. Due to two-photon absorption in silicon, however, much nonlinear research is shifting towards unconventional photonics platforms. In this work, we demonstrate the generation of an octave-spanning coherent supercontinuum in a silicon waveguide covering the spectral region from the near- to shortwave-infrared. With input pulses of 18 pJ in energy, the generated signal spans the wavelength range from the edge of the silicon transmission window, approximately 1.06 to beyond 2.4 μm, with a -20 dB bandwidth covering 1.124-2.4 μm. An octave-spanning supercontinuum was also observed at the energy levels as low as 4 pJ (-35 dB bandwidth). We also measured the coherence over an octave, obtaining , in good agreement with the simulations. In addition, we demonstrate optimization of the third-order dispersion of the waveguide to strengthen the dispersive wave and discuss the advantage of having a soliton at the long wavelength edge of an octave-spanning signal for nonlinear applications. This research paves the way for applications, such as chip-scale precision spectroscopy, optical coherence tomography, optical frequency metrology, frequency synthesis and wide-band wavelength division multiplexing in the telecom window.
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Affiliation(s)
- Neetesh Singh
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Ming Xin
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Diedrik Vermeulen
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Katia Shtyrkova
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Nanxi Li
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- John A. Paulson School of Engineering and Applied Science, Harvard University, Cambridge, MA 02138, USA
| | - Patrick T Callahan
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Emir Salih Magden
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alfonso Ruocco
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Nicholas Fahrenkopf
- College of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, NY 12203, USA
| | - Christopher Baiocco
- College of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, NY 12203, USA
| | - Bill P-P Kuo
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92039, USA
| | - Stojan Radic
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92039, USA
| | - Erich Ippen
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Franz X Kärtner
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Centre for Free Electron Laser Science (CFEL)-DESY and University of Hamburg, Hamburg 22607, Germany
| | - Michael R Watts
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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14
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Zhang Y, Kane DJ, Omenetto FG. Experimental measurement of supercontinuum coherence in tellurite photonic crystal fibers. OPTICS LETTERS 2017; 42:4857-4860. [PMID: 29216128 DOI: 10.1364/ol.42.004857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 09/25/2017] [Indexed: 06/07/2023]
Abstract
Spectral and coherence evolutions were measured for supercontinuum (SC) generated in a 2.7 cm highly nonlinear tellurite photonic crystal fiber. Numerical simulations were performed based on the generalized nonlinear Schrödinger equation with noise. The measurements show that coherence degradation first occurs after soliton fission, and then spreads to longer wavelengths as the average power of the SC increases. The solitonic coherence shows much slower degradation than the overall coherence.
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15
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Yoon Oh D, Yang KY, Fredrick C, Ycas G, Diddams SA, Vahala KJ. Coherent ultra-violet to near-infrared generation in silica ridge waveguides. Nat Commun 2017; 8:13922. [PMID: 28067233 PMCID: PMC5227738 DOI: 10.1038/ncomms13922] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 11/11/2016] [Indexed: 11/25/2022] Open
Abstract
Short duration, intense pulses of light can experience dramatic spectral broadening when propagating through lengths of optical fibre. This continuum generation process is caused by a combination of nonlinear optical effects including the formation of dispersive waves. Optical analogues of Cherenkov radiation, these waves allow a pulse to radiate power into a distant spectral region. In this work, efficient and coherent dispersive wave generation of visible to ultraviolet light is demonstrated in silica waveguides on a silicon chip. Unlike fibre broadeners, the arrays provide a wide range of emission wavelength choices on a single, compact chip. This new capability is used to simplify offset frequency measurements of a mode-locked frequency comb. The arrays can also enable mode-locked lasers to attain unprecedented tunable spectral reach for spectroscopy, bioimaging, tomography and metrology. Continuum generation in optical fibres has enabled many applications, like optical frequency combs. Here, Oh et al. demonstrate controlled dispersive-wave generation in on-chip silica waveguides, which could have a similar impact on integrated devices.
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Affiliation(s)
- Dong Yoon Oh
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, California 91125, USA
| | - Ki Youl Yang
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, California 91125, USA
| | - Connor Fredrick
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Gabriel Ycas
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Scott A Diddams
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Kerry J Vahala
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, California 91125, USA
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Guo Y, Jafari Z, Agarwal AM, Kimerling LC, Li G, Michel J, Zhang L. Bilayer dispersion-flattened waveguides with four zero-dispersion wavelengths. OPTICS LETTERS 2016; 41:4939-4942. [PMID: 27805655 DOI: 10.1364/ol.41.004939] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We propose a new type of bilayer dispersion-flattened waveguides that have four zero-dispersion wavelengths. Low and flat dispersion can be achieved by using two different material combinations, with a much smaller index contrast as compared to the previously proposed slot-assisted dispersion-flattened waveguides. Without using a nano-slot, dispersion becomes less sensitive to waveguide dimensions, which is highly desirable for high-yield device fabrication. Ultra-low dispersion, high nonlinearity, and fabrication-friendly design would make it promising for practical implementation of nonlinear photonic functions. The proposed waveguide configuration deepens our understanding of the dispersion flattening principle.
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Ciret C, Gorza SP. Scattering of a cross-polarized linear wave by a soliton at an optical event horizon in a birefringent nanophotonic waveguide. OPTICS LETTERS 2016; 41:2887-2890. [PMID: 27304314 DOI: 10.1364/ol.41.002887] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The scattering of a linear wave on an optical event horizon, induced by a cross-polarized soliton, is experimentally and numerically investigated in integrated structures. The experiments are performed in a dispersion-engineered birefringent silicon nanophotonic waveguide. In stark contrast with copolarized waves, the large difference between the group velocity of the two cross-polarized waves enables a frequency conversion almost independent of the soliton wavelength. It is shown that the generated idler is only shifted by 10 nm around 1550 nm over a pump tuning range of 350 nm. Simulations using two coupled full vectorial nonlinear Schrödinger equations fully support the experimental results.
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Johnson AR, Mayer AS, Klenner A, Luke K, Lamb ES, Lamont MRE, Joshi C, Okawachi Y, Wise FW, Lipson M, Keller U, Gaeta AL. Octave-spanning coherent supercontinuum generation in a silicon nitride waveguide. OPTICS LETTERS 2015; 40:5117-5120. [PMID: 26512533 DOI: 10.1364/ol.40.005117] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We demonstrate the generation of a supercontinuum spanning more than 1.4 octaves in a silicon nitride waveguide using sub-100-fs pulses at 1 μm generated by either a 53-MHz, diode-pumped ytterbium (Yb) fiber laser or a 1-GHz, Yb:CaAlGdO(4) (Yb:CALGO) laser. Our numerical simulations show that the broadband supercontinuum is fully coherent, and a spectral interference measurement is used to verify that the supercontinuum generated with the Yb:CALGO laser possesses a high degree of coherence over the majority of its spectral bandwidth. This coherent spectrum may be utilized for optical coherence tomography, spectroscopy, and frequency metrology.
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Dave UD, Ciret C, Gorza SP, Combrie S, De Rossi A, Raineri F, Roelkens G, Kuyken B. Dispersive-wave-based octave-spanning supercontinuum generation in InGaP membrane waveguides on a silicon substrate. OPTICS LETTERS 2015; 40:3584-3587. [PMID: 26258363 DOI: 10.1364/ol.40.003584] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We demonstrate the generation of an octave-spanning supercontinuum in InGaP membrane waveguides on a silicon substrate pumped by a 1550-nm femtosecond source. The broadband nature of the supercontinuum in these dispersion-engineered high-index-contrast waveguides is enabled by dispersive wave generation on both sides of the pump as well as by the low nonlinear losses inherent to the material. We also measure the coherence properties of the output spectra close to the pump wavelength and find that the supercontinuum is highly coherent at least in this wavelength range.
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Mayer AS, Klenner A, Johnson AR, Luke K, Lamont MRE, Okawachi Y, Lipson M, Gaeta AL, Keller U. Frequency comb offset detection using supercontinuum generation in silicon nitride waveguides. OPTICS EXPRESS 2015; 23:15440-15451. [PMID: 26193524 DOI: 10.1364/oe.23.015440] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present the first direct carrier-envelope-offset (CEO) frequency detection of a modelocked laser based on supercontinuum generation (SCG) in a CMOS-compatible silicon nitride (Si(3)N(4)) waveguide. With a coherent supercontinuum spanning more than 1.5 octaves from visible to beyond telecommunication wavelengths, we achieve self-referencing of SESAM modelocked diode-pumped Yb:CALGO lasers using standard f-to-2f interferometry. We directly obtain without amplification strong CEO beat signals for both a 100-MHz and 1-GHz pulse repetition rate laser. High signal-to-noise ratios (SNR) of > 25 dB and even > 30 dB have been generated with only 30 pJ and 36 pJ of coupled pulse energy from the megahertz and gigahertz laser respectively. We compare these results to self-referencing using a commercial photonic crystal fiber and find that the required peak power for CEO beat detection with a comparable SNR is lowered by more than an order of magnitude when using a Si(3)N(4) waveguide.
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