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Krause EE, Malka D. Optimizations of Double Titanium Nitride Thermo-Optic Phase-Shifter Heaters Using SOI Technology. SENSORS (BASEL, SWITZERLAND) 2023; 23:8587. [PMID: 37896680 PMCID: PMC10610627 DOI: 10.3390/s23208587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 10/13/2023] [Accepted: 10/18/2023] [Indexed: 10/29/2023]
Abstract
A commercial thermo-optic phase shifter (TOPS) is an efficient solution to the imbalance problem in the fabrication process of Mach-Zehnder modulator (MZM) arms. The TOPS consumes electrical power and transforms it into thermal energy, which changes the real part of the effective refractive index at the waveguide and adjusts the MZM transfer function to work in the linear region. The common model being used today is constructed with only one heater; however, this solution requires more electrical power, which can increase the transmitter system cost. To reduce the system energy cost, we propose a pioneering optimal double titanium nitride heater model under forward biasing at 1550 nm wavelength using the standard silicon-on-insulator technology. Numerical investigations were carried out on the key relative geometrical parameters, heat distribution at the silicon layer, thermal crosstalk, and laser wavelength drift. Results show that the optimal TOPS design can function with a low electrical power of 19.1 mW to achieve a π-phase shift, with a low thermal crosstalk of 0.404 and very low optical losses over 1 mm length. Thus, the proposed device can be used for improving the imbalance problem in MZMs with low electrical power consumption and low losses. This functionality can be utilized to obtain better performances in transmitter systems for data centers and long-range optical communication system applications.
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Affiliation(s)
| | - Dror Malka
- Faculty of Engineering, Holon Institute of Technology (HIT), Holon 5810201, Israel;
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Germain T, Berthe L, Panthier F, Gorny C, Traxer O, Doizi S. Assessment of Factors Involved in Laser Fiber Degradation with Thulium Fiber Laser. J Endourol 2021; 36:668-673. [PMID: 34806403 DOI: 10.1089/end.2021.0387] [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] [Indexed: 11/12/2022] Open
Abstract
Objectives: To assess the effect of various factors on laser fiber tip degradation with the thulium fiber laser (Tm-fiber): fiber stripping, adjustable laser settings (energy, frequency, peak power), and stone density. Methods: Two hundred seventy-three micrometer fibers were used with a 50W Tm-fiber. First, we assessed the evolution of power transmission with stripped and unstripped fibers submerged in saline. The laser was continuously activated for 5 minutes. The influence of each laser parameter (energy, frequency, and peak power) on fiber degradation was assessed by loss of power transmission and reduction of tip length. Second, we assessed the evolution of power transmission after 150 seconds of lithotripsy in a quasicontact mode against soft and hard BegoStones. The influence of lithotripsy with different laser settings on fiber degradation was assessed by loss of power transmission. Results: Power transmission was close to 100% with stripped fibers, while a power gain appeared for unstripped fibers after 5 minutes of laser emission. Thus, only stripped laser fibers were used during the second series of experiments. Regardless of laser settings, there was a constant loss of measured power transmission after lithotripsy with a significant difference between soft and hard stones, p < 0.0001. Power transmission was 67% and 78% against hard and soft stones, respectively. While there was no influence of peak power on power output against hard stones, there was a significant one against soft stones. Conclusions: The main determinant of loss of power transmission during lithotripsy in contact mode with Tm-fiber is the stone density. Higher loss of power transmission occurs against hard stones than soft stones. All peak powers may be used against hard stones without a difference, while high peak power appears as an additional factor of power loss against soft stones, but this decrease will not the reach the one obtained with hard stones.
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Affiliation(s)
- Thibault Germain
- Sorbonne Université, GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Paris, France.,Sorbonne Université, Service d'Urologie, AP-HP, Hôpital Tenon, Paris, France
| | - Laurent Berthe
- PIMM, UMR 8006 CNRS-Arts et Métiers ParisTech, 151 bd de l'Hôpital, Paris, France
| | - Frédéric Panthier
- Sorbonne Université, GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Paris, France.,Sorbonne Université, Service d'Urologie, AP-HP, Hôpital Tenon, Paris, France
| | - Cyril Gorny
- PIMM, UMR 8006 CNRS-Arts et Métiers ParisTech, 151 bd de l'Hôpital, Paris, France
| | - Olivier Traxer
- Sorbonne Université, GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Paris, France.,Sorbonne Université, Service d'Urologie, AP-HP, Hôpital Tenon, Paris, France
| | - Steeve Doizi
- Sorbonne Université, GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Paris, France.,Sorbonne Université, Service d'Urologie, AP-HP, Hôpital Tenon, Paris, France
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Ritchie C, Yang P, Peplinski B, Keheila M, Cheriyan S, Abourbih S, Kelln W, Baldwin DD. Jackets Off: The Impact of Laser Fiber Stripping on Power Output and Stone Degradation. J Endourol 2017; 31:780-785. [PMID: 28521539 DOI: 10.1089/end.2017.0160] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE To investigate the effect of laser fiber stripping on stone fragmentation and laser fiber power output. MATERIALS AND METHODS In a benchtop simulation of laser lithotripsy, 20 BegoStone phantoms were positioned within a ureteral model and irradiated for 10 minutes at 8 Hz and 0.8 J. A freshly cleaved 365 μm laser fiber was used for all trials, with half of the fibers also undergoing stripping. Power output was measured at 1-minute intervals, beginning with an initial prelithotripsy recording at 0 minutes. Fiber tips were imaged with scanning electron microscopy. In a single-blinded manner, final masses of residual stone fragments were measured and used to quantify stone breakdown. Independent-sample Mann-Whitney U tests were performed with significance set at p < 0.05, comparing stripped and unstripped fiber tips with respect to power output and fraction of stone fragmentation. RESULTS Mean power output after 1 minute of lasing was significantly greater in unstripped laser fibers (p = 0.015), while fibers, whether stripped or not, demonstrated no significant output differences prelithotripsy or at any time from 2 to 10 minutes. However, stripped laser fibers achieved significantly increased stone breakdown compared to unstripped fibers (p = 0.004), fragmenting 63 mg (25%) more of the initial stone mass per trial. CONCLUSIONS Although unstripped laser fibers provided superior power output at 1 minute, output at all other time points was similar between stripped and unstripped fibers. However, despite similar optical output, stripped laser fibers achieved greater stone fragmentation, possibly due to improved contact between stone and fiber tip.
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Affiliation(s)
- Cayde Ritchie
- 1 Department of Urology, Loma Linda University Medical Center , Loma Linda, California
| | - Patrick Yang
- 1 Department of Urology, Loma Linda University Medical Center , Loma Linda, California
| | - Brandon Peplinski
- 1 Department of Urology, Loma Linda University Medical Center , Loma Linda, California
| | - Mohamed Keheila
- 1 Department of Urology, Loma Linda University Medical Center , Loma Linda, California
| | - Salim Cheriyan
- 1 Department of Urology, Loma Linda University Medical Center , Loma Linda, California
| | - Samuel Abourbih
- 1 Department of Urology, Loma Linda University Medical Center , Loma Linda, California
| | - Wayne Kelln
- 2 Department of Earth and Biological Sciences, Loma Linda University , Loma Linda, California
| | - D Duane Baldwin
- 1 Department of Urology, Loma Linda University Medical Center , Loma Linda, California
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Peplinski B, Faaborg D, Miao E, Alsyouf M, Myklak K, Kelln W, Baldwin DD. The Effect of Laser Fiber Cleave Technique and Lithotripsy Time on Power Output. J Endourol 2016; 30:678-84. [DOI: 10.1089/end.2015.0835] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Brandon Peplinski
- Department of Urology, Loma Linda University Medical Center, Loma Linda, California
| | - Daniel Faaborg
- Department of Urology, Loma Linda University Medical Center, Loma Linda, California
| | - Edna Miao
- Department of Urology, Loma Linda University Medical Center, Loma Linda, California
| | - Muhannad Alsyouf
- Department of Urology, Loma Linda University Medical Center, Loma Linda, California
| | - Kristene Myklak
- Department of Urology, Loma Linda University Medical Center, Loma Linda, California
| | - Wayne Kelln
- Department of Urology, Loma Linda University Medical Center, Loma Linda, California
| | - D. Duane Baldwin
- Department of Urology, Loma Linda University Medical Center, Loma Linda, California
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Romanos GE, Belikov AV, Skrypnik AV, Feldchtein FI, Smirnov MZ, Altshuler GB. Uncovering dental implants using a new thermo-optically powered (TOP) technology with tissue air-cooling. Lasers Surg Med 2015; 47:411-20. [DOI: 10.1002/lsm.22360] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Georgios E. Romanos
- Department of Periodontology; Eastman Institute for Oral Health, University of Rochester; Rochester New York 11794-8700
- Department of Periodontology; Stony Brook University, School of Dental Medicine; Stony Brook New York 11794-8700
| | - Andrey V. Belikov
- Department of Laser Technology and Biomedical Optics; St. Petersburg National Research University of Information Technologies, Mechanics and Optics; Saint Petersburg Russia
- Dental Photonics, Inc.; 1600 Boston-Providence Highway; Walpole Massachusetts 02081
| | - Alexei V. Skrypnik
- Department of Laser Technology and Biomedical Optics; St. Petersburg National Research University of Information Technologies, Mechanics and Optics; Saint Petersburg Russia
| | - Felix I. Feldchtein
- Dental Photonics, Inc.; 1600 Boston-Providence Highway; Walpole Massachusetts 02081
| | - Michael Z. Smirnov
- Department of Laser Technology and Biomedical Optics; St. Petersburg National Research University of Information Technologies, Mechanics and Optics; Saint Petersburg Russia
| | - Gregory B. Altshuler
- Dental Photonics, Inc.; 1600 Boston-Providence Highway; Walpole Massachusetts 02081
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Vassantachart JM, Lightfoot M, Yeo A, Maldonado J, Li R, Alsyouf M, Martin J, Lee M, Olgin G, Baldwin DD. Laser Fiber Cleaving Techniques: Effects on Tip Morphology and Power Output. J Endourol 2015; 29:84-9. [DOI: 10.1089/end.2014.0175] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Affiliation(s)
| | - Michelle Lightfoot
- Department of Urology, Loma Linda University Medical Center, Loma Linda, California
| | - Alexander Yeo
- Department of Urology, Loma Linda University Medical Center, Loma Linda, California
| | - Jonathan Maldonado
- Department of Urology, Loma Linda University Medical Center, Loma Linda, California
| | - Roger Li
- Department of Urology, Loma Linda University Medical Center, Loma Linda, California
| | - Muhannad Alsyouf
- Department of Urology, Loma Linda University Medical Center, Loma Linda, California
| | - Jacob Martin
- Department of Urology, Loma Linda University Medical Center, Loma Linda, California
| | - Michael Lee
- Department of Urology, Loma Linda University Medical Center, Loma Linda, California
| | - Gaudencio Olgin
- Department of Urology, Loma Linda University Medical Center, Loma Linda, California
| | - D. Duane Baldwin
- Department of Urology, Loma Linda University Medical Center, Loma Linda, California
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Marks AJ, Mues AC, Knudsen BE, Teichman JM. Holmium:Yttrium-Aluminum-Garnet Lithotripsy Proximal Fiber Failures From Laser and Fiber Mismatch. Urology 2008; 71:1049-51. [DOI: 10.1016/j.urology.2007.10.060] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2007] [Revised: 09/28/2007] [Accepted: 10/26/2007] [Indexed: 10/22/2022]
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Abstract
In esthetic dentistry, expanding the evaluation beyond the teeth is necessary to achieve a truly desirable result. The lips, attached and unattached mucosa, free gingival margin, and osseous position and contours must be considered and changed if necessary. Although many treatment modalities are available to accomplish these modifications, the use of lasers of varying wavelengths provides advantages not possible by other means. Lasers are often thought of as generic instruments, but different laser wavelengths function differently, and each has its place in the esthetic continuum. Diode, neodymium:YAG, CO(2) and erbium lasers each have advantages that can be exploited to maximum effect and disadvantages that must be taken into consideration. A thorough understanding of their mechanism of action, their tissue effects, and laser safety is vital to obtaining excellent results.
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Affiliation(s)
- Kenneth S Magid
- Department of Cariology and Comprehensive Care, New York University College of Dentistry, 345 East 24th Street, New York, NY 10010, USA.
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Lee H, Ryan RT, Teichman JMH, Landman J, Clayman RV, Milner TE, Welch AJ. Effect of lithotripsy on holmium:YAG optical beam profile. J Endourol 2003; 17:63-7. [PMID: 12689396 DOI: 10.1089/08927790360587351] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
PURPOSE To determine the effect of holmium:YAG lithotripsy on the optical beam profile. MATERIALS AND METHODS Beam profiles of the laser light from holmium:YAG optical fiber systems were characterized with a pyroelectric camera. Beam profiles were measured with 272-microm and 365-microm optical fibers both straight and bent to simulate lower-pole ureteronephroscopy. Struvite calculi were irradiated. Beam profiles and energy outputs were characterized for the fibers before and after ablation. Ablation crater geometry was characterized with optical coherence tomography. RESULTS Undamaged, straight fibers produced a near-Gaussian beam profile. Craters showed a similar near-Gaussian shape. Undamaged, bent 272-microm fibers produced a near-Gaussian beam but slightly flatter profile than the straight fiber. The bent 272-microm fiber transmitted 99% to 100% of the energy, similar to the 100% transmission of the straight fibers. After ablation, measured energy output dropped by 30% within 50 pulses at 0.2 J pulse energy. The damaged fibers produced irregular beam profiles with hot spots. Craters showed irregular contours. CONCLUSIONS During Ho:YAG lithotripsy, the beam profile at the optical fiber tip approaches a Gaussian distribution. This shape corresponds to the crater produced on the stone surface. With further ablation, the beam profile becomes erratic and unpredictable, with loss of lithotripsy efficiency. The findings provide further insight into the photothermal mechanism of Ho:YAG lithotripsy.
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Affiliation(s)
- Ho Lee
- Department of Mechanical Engineering, The University of Texas, Austin, Texas, USA
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Spore SS, Teichman JM, Corbin NS, Champion PC, Williamson EA, Glickman RD. Holmium: YAG lithotripsy: optimal power settings. J Endourol 1999; 13:559-66. [PMID: 10597125 DOI: 10.1089/end.1999.13.559] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE We tested the hypothesis that holmium:YAG laser lithotripsy speed is best maximized by using low pulse energy at high pulse frequency. MATERIALS AND METHODS To demonstrate that optical fiber damage increases with pulse energy and irradiation, the 365-microm optical fiber irradiated calcium hydrogen phosphate dihydrate (CHPD), calcium oxalate monohydrate (COM), cystine, magnesium ammonium phosphate hexahydrate (MAPH), and uric acid calculi at pulse energies of 0.5 to 2.0 J. Optical energy output was measured with an energy detector after 10 J to 200 J of total energy. To demonstrate that lithotripsy efficiency varies with power, fragmentation was measured at constant power settings at total energies of 200 J and 1 kJ with the 365-microm optical fiber. Fragmentation was measured for the 272-microm optical fiber at pulse energies of 0.5 J to 1.5 J at 10 Hz. To demonstrate that low pulse energy produces smaller fragments than high pulse energy, fragment size was characterized for COM and uric acid calculi after 0.25 kJ of irradiation using the 272-microm to 940-microm optical fibers at 0.5 J to 1.5 J. RESULTS Damage to the 365-microm optical fiber was greatest for irradiation of CHPD, followed by MAPH, and COM (P<0.001). There was no significant optical fiber damage after cystine and uric acid lithotripsy. For the 365-microm optical fiber and CHPD, fragmentation after 200 J was greatest for pulse energies < or =1.0 J (P< 0.001). For other compositions, fragmentation was not statistically different among the power settings for constant irradiation. No significant difference was noted in fragmentation for any composition at different pulse energies (1.0 v. 2.0 J) for 1-kJ irradiation. However, for all compositions, the calculated lithotripsy speed was greatest at high power settings (P<0.001). For the 272-microm optical fiber, CHPD fragmentation was greatest for the 1.0-J pulse energy. The mean fragment size and relative quantity of fragments > or =2 mm both increased as pulse energy increased. CONCLUSIONS Optical fiber degradation varies with stone composition, irradiation, and pulse energy. Holmium:YAG lithotripsy speed is maximized with higher power (either increased pulse energy or higher pulse frequency). Because low pulse energy may be safer and yields smaller fragments than high pulse energy, holmium:YAG lithotripsy speed is best increased by using pulse energies < or =1.0 J at a high repetition rate.
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Affiliation(s)
- S S Spore
- Division of Urology, The University of Texas Health Science Center San Antonio, 78284-7845, USA
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Abstract
PURPOSE We test the hypothesis that holmium:YAG lithotripsy efficiency varies with optical fiber size and energy settings (energy density). MATERIALS AND METHODS The 272, 365, 550 and 940 microm. optical fibers delivered 1 kJ. total holmium:YAG energy to calcium oxalate monohydrate calculi at energy output/pulse of 0.2 to 1.5 J. Stone mass loss was measured for each fiber energy setting. Stone crater width was characterized for single energy pulses. Fiber energy outputs were compared before and after lithotripsy. RESULTS Stone mass loss correlated inversely with optical fiber diameter (p <0.05). Stone loss correlated with energy/pulse for the 365, 550 and 940 microm. fibers (p <0.001). The 272 and 365 microm. fibers yielded equivalent stone loss at 0.2 and 0.5 J. per pulse. At energies of 1.0 J. per pulse or greater the 272 microm. optical fiber was prone to damage, and yielded reduced energy output and stone loss compared to the 365 microm. fiber (p <0.01). Stone crater width for single pulse energies correlated with energy settings for all fibers (p <0.001). CONCLUSIONS Lithotripsy efficiency with the holmium:YAG laser depends on pulse energy output and diameter of the optical delivery fiber, implying that lithotripsy efficiency correlates with energy density. The 365 microm. fiber is indicated for most lithotripsy applications. The 272 microm. fiber is susceptible to damage and inefficient energy transmission at energies of 1.0 J. per pulse or greater. The 272 microm. fiber is indicated at energies of less than 1.0 J. per pulse for small caliber ureteroscopes or when maximal flexible ureteroscope deflection is required.
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Affiliation(s)
- G J Vassar
- Department of Ophthalmology, University of Texas Health Science Center, San Antonio, USA
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Laser literature watch. JOURNAL OF CLINICAL LASER MEDICINE & SURGERY 1997; 15:309-17. [PMID: 9641089 DOI: 10.1089/clm.1997.15.309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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