Browsing by Author "Lai, Yinchieh"

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10 GHz Bound Soliton Mode-locking in an Environmentally Stable FM Mode-locked Er-doped Fiber Soliton Laser
(2014)
Luo, Cheng-Jhih
;
Wang, Sheng-Min
;
Lai, Yinchieh
;
光電工程學系
;
Department of Photonics
We experimentally demonstrate an environmentally stable 10 GHz FM mode-locked Er-doped fiber soliton laser that can produce stable bound solitons even when there is no equivalent fast saturable absorption mechanism inside the cavity.
250-GHz Passive Harmonic Mode-Locked Er-Doped Fiber Laser by Dissipative Four-Wave Mixing With Silicon-Based Micro-Ring
(2013-10-01)
Jyu, Siao-Shan
;
Yang, Ling-Gang
;
Wong, Chi-Yan
;
Yeh, Chien-Hung
;
Chow, Chi-Wai
We propose and demonstrate a 250-GHz high-repetition-rate mode-locked Er-doped fiber laser, which utilizes a silicon micro-ring resonator (SMRR). The SMRR acts as an optical comb filter to help achieve passive mode-locking through the dissipative four-wave-mixing effect induced by a piece of high nonlinear fiber. A short section of polarization-maintaining fiber is inserted in the cavity to induce birefringence filtering to significantly enhance the stability of the proposed laser through the combined effects of optical filtering and nonlinear spectral broadening. The laser can operate about 2 and 6 nm in the case of 1.48-ps and 875-fs output pulsewidth, with 3-dB bandwidth, respectively. The laser can remain mode locked, during our measurement time, without any cavity length or temperature feedback control.
300 GHz Bound Pulse Generation in a Filter-Assisted Harmonic Mode-Locked Er-doped Fiber Laser with 20 GHz Phase Modulation
(2014)
Wang, Sheng-Min
;
Jyu, Siao-Shan
;
Lai, Yinchieh
;
光電工程學系
;
Department of Photonics
By inserting a section of PM fiber for birefringence interference filtering with 100 GHz spacing, stable 300 GHz bound pulses have been successfully generated in a harmonic mode-locked Er-doped fiber laser with 20 GHz phase modulation frequency.
A 110 GHz passive mode-locked fiber laser based on a nonlinear silicon-micro-ring-resonator
(2014-06-01)
Yang, Ling-Gang
;
Jyu, Siao-Shan
;
Chow, Chi-Wai
;
Yeh, Chien-Hung
;
Wong, Chi-Yan
Mode-locked fiber lasers have many important applications in science and engineering. In this work, we demonstrate for the first time a 110 GHz high repetition rate mode-locked fiber laser using a silicon-based micro-ring resonator (SMRR) to act as an intra-cavity optical comb filter, as well as an optical nonlinear element. No electrical bias for the SMRR is required to reduce free carrier absorption. The SMRR has a free spectral range of 0.88 nm, enforcing laser mode-locking at the 110 GHz high rate. The optical nonlinearity of the SMRR also supports the dissipative four-wave mixing effect for generating the mode-locked optical pulse trains. The mode-locked pulse-width, optical 3 dB spectral bandwidth and the time-bandwidth product (TBP) are experimentally measured under different pump currents to the erbium-doped fiber-amplifier module inside the laser cavity. The relative intensity noise and the line-width of the proposed laser are also evaluated. Furthermore, a long-term monitoring is performed. The experimental results show that the optical pulse train generated by the SMRR-based mode-locked fiber laser has a 2.6 ps pulse-width (pump current at 400 mA) at a 110 GHz high repetition rate, narrow line-width (1 kHz), high stability (under observation of an hour), and nearly Gaussian transform-limited (TBP is 0.455).
A 110 GHz passive mode-locked fiber laser based on a nonlinear silicon-micro-ring-resonator
(2014-06-01)
Yang, Ling-Gang
;
Jyu, Siao-Shan
;
Chow, Chi-Wai
;
Yeh, Chien-Hung
;
Wong, Chi-Yan
Mode-locked fiber lasers have many important applications in science and engineering. In this work, we demonstrate for the first time a 110 GHz high repetition rate mode-locked fiber laser using a silicon-based micro-ring resonator (SMRR) to act as an intra-cavity optical comb filter, as well as an optical nonlinear element. No electrical bias for the SMRR is required to reduce free carrier absorption. The SMRR has a free spectral range of 0.88 nm, enforcing laser mode-locking at the 110 GHz high rate. The optical nonlinearity of the SMRR also supports the dissipative four-wave mixing effect for generating the mode-locked optical pulse trains. The mode-locked pulse-width, optical 3 dB spectral bandwidth and the time-bandwidth product (TBP) are experimentally measured under different pump currents to the erbium-doped fiber-amplifier module inside the laser cavity. The relative intensity noise and the line-width of the proposed laser are also evaluated. Furthermore, a long-term monitoring is performed. The experimental results show that the optical pulse train generated by the SMRR-based mode-locked fiber laser has a 2.6 ps pulse-width (pump current at 400 mA) at a 110 GHz high repetition rate, narrow line-width (1 kHz), high stability (under observation of an hour), and nearly Gaussian transform-limited (TBP is 0.455).
A new dispersioin measurement apparatus by a periodic wavelengh-scanning pulse laser
(2009)
Jyu, Siao-Shan
;
Liu, Shiou-Fong
;
Hsiang, Wei-Wei
;
Lai, Yinchieh
;
光電工程學系
A new fiber group velocity dispersion (GVD) measurement method has been reported and demonstrated by using a periodic wavelength-scanning pulse laser such as an asynchronously modelocked Er-fiber soliton laser and simple RF spectral measurement.
A simple group velocity dispersion measurement method by RF spectral periodic pulse timing variation characterization
(2009)
Liu, Shiou-Fong
;
Jyu, Siao-Shan
;
Chang, Hon-Chieh
;
Hsiang, Wei-Wei
;
Lai, Yinchieh
By measuring the dispersion-induced periodic pulse timing variation with a wavelength-swept pulse light source and a RF spectrum analyzer, the fiber group velocity dispersion can be determined with excellent accuracy. (C)2009 Optical Society of America
An Electrically Tunable Polarizer for a Fiber System Based on a Polarization-Dependent Beam Size Derived From a Liquid Crystal Lens
(2014-06-01)
Chen, Michael
;
Chen, Chyong-Hua
;
Lai, Yinchieh
;
Lu, Yan-qing
;
Lin, Yi-Hsin
A broadband electrically tunable variable polarizer for fiber systems based on a liquid crystal lens is proposed and demonstrated. The polarization selectivity is based on a polarization-sensitive coupling efficiency to the fiber in the fiber system. For an incident ordinary ray, the output beam size remains the same as that of the incident beam, which results in low coupling efficiency. For an incident extraordinary ray (e-ray), the output beam size is close to the size of the fiber core, giving rise to high coupling efficiency because of the lens effect. Moreover, the output beam size of the e-ray can be electrically controlled, thus allowing the optical attenuation to be manipulated. In our experiments, the polarizationdependent loss from the visible to the near-infrared spectral region was approximately 12 dB. Such a broadband electrically variable polarizer may be applied to various designs for fiberoptic sensing devices and polarization-sensitive optical instruments.
An Electrically Tunable Polarizer for a Fiber System Based on a Polarization-Dependent Beam Size Derived From a Liquid Crystal Lens
(2014-06-01)
Chen, Michael
;
Chen, Chyong-Hua
;
Lai, Yinchieh
;
Lu, Yan-qing
;
Lin, Yi-Hsin
A broadband electrically tunable variable polarizer for fiber systems based on a liquid crystal lens is proposed and demonstrated. The polarization selectivity is based on a polarization-sensitive coupling efficiency to the fiber in the fiber system. For an incident ordinary ray, the output beam size remains the same as that of the incident beam, which results in low coupling efficiency. For an incident extraordinary ray (e-ray), the output beam size is close to the size of the fiber core, giving rise to high coupling efficiency because of the lens effect. Moreover, the output beam size of the e-ray can be electrically controlled, thus allowing the optical attenuation to be manipulated. In our experiments, the polarizationdependent loss from the visible to the near-infrared spectral region was approximately 12 dB. Such a broadband electrically variable polarizer may be applied to various designs for fiberoptic sensing devices and polarization-sensitive optical instruments.
Analysis of Thermo-Optic Tunable Dispersion-Engineered Short-Wavelength-Pass Tapered-Fiber Filters
(2009-07-01)
Chou, Sen-Yih
;
Hsu, Kuei-Chu
;
Chen, Nan-Kuang
;
Liaw, Shien-Kuei
;
Chih, Yu-Syun
Thermo-optic tunable short-wavelength-pass tapered-fiber filters based on fundamental-mode cutoff mechanism are realized experimentally and analyzed theoretically. The effects of material and waveguide dispersion are investigated and the optimal tapered fiber structures for attaining high-spectral cutoff slope and high-rejection efficiency are determined.
Asynchronous Harmonic Mode Locking in an All-Normal Dispersion Yb-Doped Fiber Laser
(2013-02-01)
Wang, Sheng-Min
;
Jyu, Siao-Shan
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Hsiang, Wei-Wei
;
Lai, Yinchieh
;
光電工程學系
We present detailed experimental and theoretical results to demonstrate the possibility of asynchronous harmonic mode locking in an all-normal dispersion fiber laser. In contrast to asynchronous soliton mode-locking operation in the anomalous dispersion regime, more profound laser dynamics are found. The experimentally demonstrated 10-GHz asynchronous harmonic mode-locked Yb-doped fiber laser exhibits an excellent super-mode noise suppression ratio in the RF spectrum with picosecond output pulsewidth.
Bandpass Filter With Variable Bandwidth Based on a Tapered Fiber With External Polymer Cladding
(2009-07-01)
Hsu, Kuei-Chu
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Chen, Nan-Kuang
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Chou, Sen-Yih
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Liaw, Shien-Kuei
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Lai, Yinchieh
A thermo-optical bandwidth-variable fiber-based bandpass filter is experimentally and theoretically demonstrated by simply utilizing a tapered standard single-mode fiber covered with a dispersive polymer layer. The 3-dB spectral bandwidth can be tuned from 250 to 500 nm with the filter center wavelength around 1 mu m.
Bandwidth-Variable Bandpass Filter based on Dispersion Engineered Tapered Fiber with External Polymer Cladding
(2009)
Hsu, Kuei-Chu
;
Chen, Nan-Kuang
;
Chou, Sen-Yih
;
Liaw, Shien-Kuei
;
Lai, Yinchieh
A simple thermo-optic bandwidth-variable fiber-based bandpass filter is demonstrated by using a tapered standard single mode fiber covered with a dispersive polymer layer. The 3 dB spectral bandwidth can be tuned from 250 rim with a Gaussian shape to 500 nm with a flat-top shape. (C) 2008 Optical Society of America
BJT-Type Optical Phase Shifter With Small Power Consumption and Fast Response Time on a Silicon Photonics Foundry Platform
(2020-03-01)
Chao, Rui-Lin
;
Ahmad, Zohauddin
;
Chen, Jason
;
Lai, Yinchieh
;
Shi, Jin-Wei
We demonstrate a novel optical phase shifter with a bipolar junction transistor (BJT) type of device structure based on the silicon photonics foundry platform. By operating such a device in saturation mode, we obtain measured output I-EC-V-EC characteristics very similar to those of an ideal diode, which has a nearly zero turn-on voltage and an extremely small differential resistance. The huge amount of injected current under a small voltage swing (0.1 V) in the operation window makes it possible to obtain significant plasma induced change of the refractive index in the optical waveguide with an extremely small driving-voltage. The device has a small foot-print (500 mu m in length), but exhibits small static power consumption for the pi phase-shift (P-pi: 4.1 mW), reasonable propagation loss (0.02 dB/mu m), small driving-voltage (V-pi: 0.12 V), fast switching time (rise/fall <1.6/1 ns), a residue amplitude modulation (RAM) as small as 0.18 dB, and a very-low power consumption (0.45 mW) during dynamic operation.
Bound Soliton Fiber Laser Mode-Locking Without Saturable Absorption Effect
(2016-08-01)
Luo, Cheng-Jhih
;
Wang, Sheng-Min
;
Lai, Yinchieh
;
光電工程學系
;
光電工程研究所
Stable bound soliton laser mode-locking is experimentally demonstrated in an environmentally stable hybrid mode-locked Er-doped fiber laser without incorporating (equivalent) nonlinear saturable absorption effects. The laser has a sigma-type cavity and exhibits a higher threshold for single to bound soliton mode-locking state transition. A nonlinear eigenstate analysis based on the master equation model and the concept of steady-state lasing gain is developed to more physically explain the observed mode-locking state transition phenomena.
Characteristics of a 40 GHz asynchronous harmonic mode-locked Er-doped fiber laser
(2017-01-01)
Wen, Chih-Chieh
;
Luo, Cheng-Jhih
;
Wang, Sheng-Min
;
Lai, Yinchieh
;
光電工程學系
A 40 GHz asynchronous harmonic mode-locked Er-doped fiber laser is demonstrated for the first time. Long-term stability is achieved through low-frequency electronic feedback and the impact of modulation depth on allowable detuning range is investigated.
Characteristics of a low repetition rate passively mode-locked Yb-doped fiber laser in an all-normal dispersion cavity
(2013-02-01)
Lin, Ja-Hon
;
Jhu, Jia-Liang
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Jyu, Siao-Shan
;
Lin, Ting-Chun
;
Lai, Yinchieh
The lasing characteristics of a 365 kHz low repetition rate Yb-doped fiber laser operated in an all-normal dispersion cavity and mode-locked by the nonlinear polarization rotation mechanism are investigated in detail. As the pump power increases, the laser exhibits two transition routes when evolved from the continuous-wave (CW) state to the mode-locked (ML) state. In one evolution route the Q-switched mode-locked (QML) state is sandwiched between the CW and ML states, whereas in the other more interesting evolution route the hysteresis transition between the CW and ML states is found for the first time. Under the mode-locking operation, the laser generates sub-nanosecond pulses with linear dependence of pulsewidth on bandwidth under different pump powers, indicating the presence of giant linear chirps on the laser output pulses.
Characteristics of an Asynchronous Rational Harmonic Mode-Locked Er-Fiber Laser
(2010)
Chang, Chia-Hao
;
Jyu, Siao-Shan
;
Hsiang, Wei. -Wei.
;
Lai, Yinchieh
;
光電工程學系
High repetition rate ultra-short optical pulse trains from an asynchronous rational harmonic mode-locked (ARHML) Er-fiber laser are experimentally demonstrated and studied. This new laser exhibits obvious advantages of pulse amplitude equalization when compared to conventional rational harmonic mode-locked fiber lasers.
Classical Analog of Electromagnetically Induced Transparency in the Visible Range With Ultra-Compact Plasmonic Micro-Ring Resonators
(2015-07-01)
Hsu, Yi-Jang
;
Cheng, Bo Han
;
Lai, Yinchieh
;
Tsai, Din Ping
;
光電工程學系
We theoretically show that it should be possible to demonstrate Electromagnetic-Induced-Transparency-like (EIT-like) effects in the visible range by using ultra-compact plasmonic micro-ring resonators with mu m(2) order foot print. By using the finite-difference time-domain (FDTD) numerical method and the coupled mode theory (CMT) collaboratively, the transmission intensity, phase, and group delay spectra of the coupled plasmonic ring resonators are theoretically calculated with the inclusion of metallic loss and dispersion through the Drude model. The interference induced transmission peak can be successfully achieved through suitable design of the plasmonic ring resonator structure.
CW-pumped evanescent amplification based on side-polished fiber with heavily Er3+-doped glass overlay
(2006-08-01)
Chen, Nan-Kuang
;
Zhang, Liyan
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Hsu, Kuei-Chu
;
Hu, Lili
;
Chi, Sien
A novel diffractive-pumping scheme is proposed to improve the evanescent amplification using blazed fiber grating for the first time. We also investigate the cw-pumped-evanescent amplification at 1.55 mu m wavelength with the relative optical gain pumped at 1480 nm of around 2 dB based on side-polished fiber with the effective interaction length as long as 16 mm and with a heavily Er3+-doped (N-Er(3+) > 1.19 x 10(21) ions/cm(3)), low refractive index (n(1550) < 1.47) glass overlay, which has no concentration quenching (tau(f) = 9.0 ms).