Browsing by Author "Yang, Ling-Gang"

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110 GHz hybrid mode-locked fiber laser with enhanced extinction ratio based on nonlinear silicon-on-insulator micro-ring-resonator (SOI MRR)
(2016-03)
Liu, Yang
;
Hsu, Yung
;
Chow, Chi-Wai
;
Yang, Ling-Gang
;
Yeh, Chien-Hung
We propose and experimentally demonstrate a new 110 GHz high-repetition-rate hybrid mode-locked fiber laser using a silicon-on-insulator microring-resonator (SOI MRR) acting as the optical nonlinear element and optical comb filter simultaneously. By incorporating a phase modulator (PM) that is electrically driven at a fraction of the harmonic frequency, an enhanced extinction ratio (ER) of the optical pulses can be produced. The ER of the optical pulse train increases from 3 dB to 10 dB. As the PM is only electrically driven by the signal at a fraction of the harmonic frequency, in this case 22 GHz (110 GHz/5 GHz), a low bandwidth PM and driving circuit can be used. The mode-locked pulse width and the 3 dB spectral bandwidth of the proposed mode-locked fiber laser are measured, showing that the optical pulses are nearly transform limited. Moreover, stability evaluation for an hour is performed, showing that the proposed laser can achieve stable mode-locking without the need for optical feedback or any other stabilization mechanism.
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.
56 Gb/s OOK transmission in robust and bend-insensitive GGP 80-m ultra-large-core (ULC) MMF for lightpeak
(2015-03-01)
Chow, Chi-Wai
;
Yang, Ling-Gang
;
Sung, Jiun-Yu
;
Su, Hong-Quan
;
Yeh, Chien-Hung
We demonstrate for the first time a recorded 56-Gb/s transmission in a new type robust and bend-insensitive glass-glass-polymer structured 80-m ultra-large-core multimode fiber (ULCMMF) using simple and single-polarization on-off-keying for Lightpeak. The LCMMF design is presented. Experimental results show that the ULCMMF could be a good choice for consumer applications in the near future.
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).
Compatibility of Silicon Mach-Zehnder Modulators for Advanced Modulation Formats
(2013-08-01)
Xu, Ke
;
Yang, Ling-Gang
;
Sung, Jiun-Yu
;
Chen, Yimin M.
;
Cheng, Zhenzhou Z.
Silicon photonics which is compatible with mature complementary metal oxide semiconductor (CMOS) fabrication process has been extensively demonstrated for monolithic integration of photonic and electrical circuits. We show that an integrated silicon Mach-Zehnder modulator (MZM) may be used for advanced modulation formats despite the nonlinear dependence of refractive index change with applied voltage in the free-carrier depletion modulator. We experimentally demonstrated the use of a silicon MZM for direct detection optical orthogonal frequency division multiplexing (DDO-OFDM) modulation with advanced data formats of quadrature phase-shift keying (QPSK), 8 phase-shift keying (8PSK) and 16-quadrature amplitude modulation (16-QAM). The measured bit error rate performance of the back-to-back and 50 km single mode fiber transmission of each format is well below the forward error correction limit.
Design and characterization of large-core optical fiber for Light Peak applications
(2012-01-01)
Chow, Chi-Wai
;
Yeh, Chien-Hung
;
Yang, Ling-Gang
;
Sung, Jiun-Yu
;
Huang, Sung-Ping
Bandwidth demand for transferring data among different consumer electronic products is increasing rapidly. Due to issues of high propagation loss, electromagnetic interference, and limited bandwidth-distance product of the present copper-based electrical cables, consumer electronic devices may not provide the bandwidth required for future high-capacity applications. The Intel Corporation has proposed Light Peak technology, allowing data transfer between electronic devices at 10 Gb/s in optical domain. To establish a reliable Light Peak connection, robust optical fiber is highly required. In this paper, we discuss the fabrication and characterization of a new type of 80-mu m large-core optical fiber. We perform 10 Gb/s bit-error-rate measurements using 850 and 1550-nm transceivers. The results show that even though we have enlarged the fiber core diameter by 60% (from 50 to 80 mu m) in order to increase the laser-to-fiber alignment tolerance, transmission bandwidth and distance required by Light Peak can still be achieved in this new type of large-core optical fiber. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.OE.51.1.015006]
Design and characterization of large-core optical fiber for Light Peak applications
(2012-01-01)
Chow, Chi-Wai
;
Yeh, Chien-Hung
;
Yang, Ling-Gang
;
Sung, Jiun-Yu
;
Huang, Sung-Ping
Bandwidth demand for transferring data among different consumer electronic products is increasing rapidly. Due to issues of high propagation loss, electromagnetic interference, and limited bandwidth-distance product of the present copper-based electrical cables, consumer electronic devices may not provide the bandwidth required for future high-capacity applications. The Intel Corporation has proposed Light Peak technology, allowing data transfer between electronic devices at 10 Gb/s in optical domain. To establish a reliable Light Peak connection, robust optical fiber is highly required. In this paper, we discuss the fabrication and characterization of a new type of 80-mu m large-core optical fiber. We perform 10 Gb/s bit-error-rate measurements using 850 and 1550-nm transceivers. The results show that even though we have enlarged the fiber core diameter by 60% (from 50 to 80 mu m) in order to increase the laser-to-fiber alignment tolerance, transmission bandwidth and distance required by Light Peak can still be achieved in this new type of large-core optical fiber. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.OE.51.1.015006]
Multi-Bound Pulse State in a 250 GHz Mode-Locked Fiber Laser Based on a Silicon Micro-Ring Resonator
(2013-01-01)
Jyu, Siao-Shan
;
Yang, Ling-Gang
;
Wong, Chi Yan
;
Yeh, Chien-Hung
;
Chow, Chi-Wai
A 250 GHz passive mode-locked Er-doped fiber laser with a silicon-based micro-ring resonator is demonstrated experimentally. Besides the single pulse operation at 250 GHz, we also observe an interesting multi-bound pulse operation state.
Narrow line-width single-longitudinal-mode fiber laser using silicon-on-insulator based micro-ring-resonator
(2016-02)
Liu, Yang
;
Hsu, Yung
;
Hsu, Chin-Wei
;
Yang, Ling-Gang
;
Chow, Chi-Wai
In this work, we propose and demonstrate a stable single-longitudinal-mode (SLM) fiber laser with narrow line-width by using an integrated silicon-on-insulator micro-ring resonator (SOI MRR) and two subsidiary fiber rings for the first time, to the best of our knowledge. The laser is tunable over the wavelength range from 1546 to 1570 nm, with only step tuning of 2 nm steps. A maximum 49 dB side mode suppression ratio (SMSR) can be achieved. The compact SOI MRR provides a large free-spectral-range (FSR), while the subsidiary rings provide Vernier effect producing a single lasing mode. The FSR of the SOI MRR can be very large and controllable (since it is easy to fabricate small SOI MRR when compared with making small fiber-rings) using the complementary-metal-oxide-semiconductor (CMOS) compactable SOI fabrication processes. In our proposed laser, the measured single side-band (SSB) spectrum shows that the densely spaced longitudinal modes can be significantly suppressed to achieve SLM. The laser linewidth is only 3.5 kHz measured by using the self-heterodyne method. 30 min stability evaluation in terms of lasing wavelength and optical power is performed; showing the optical wavelength and power are both very stable, with fluctuations of only 0.02 nm and 0.8 dB, respectively.
S-band pulse generation by polarization additive-pulse mode-locking in an erbium-doped all-fiber ring laser
(2014-01-01)
Yang, Ling-Gang
;
Jyu, Siao-Shan
;
Chow, Chi-Wai
;
Yeh, Chien-Hung
;
Lai, Yinchieh
An all-fiber S-band mode-locked Er-doped fiber ring laser operated at 1503 nm is experimentally demonstrated by utilizing the polarization additive-pulse mode-locking (P-APM) mechanism. To the best of our knowledge, it is the first P-APM mode-locked fiber laser operating in the S-band. The gain medium is an S-band Er-doped fiber amplifier (EDFA) composed of two Er-doped fiber stages with the technique of depressed-cladding to cut off the fundamental mode. Stable single-pulse operation is achieved within the available pump power range. Besides, characterization of the S-band EDFA module, such as the wavelength dependences of the gain and noise figure, the slope efficiency, as well as the dependence of the pump power on the gain for different input powers is performed. In addition, analysis of the proposed S-band mode-locked fiber laser, such as the pump power dependence of the pulse-width and optical bandwidth, and pulse-width compression is also provided.
Stable and wavelength-tunable RSOA- and SOA-based fiber ring laser
(2014-06-01)
Yeh, Chien-Hung
;
Sung, Jiun-Yu
;
Yang, Ling-Gang
;
Chow, Chi-Wai
;
Chen, Jing-Heng
In this work, we propose and experimentally investigate a wavelength-tunable fiber ring laser architecture by using the reflective semiconductor optical amplifier (RSOA) and semiconductor optical amplifier (SOA). Here, the wavelength tuning range from 1538.03 to 1561.91 nm can be obtained. The measured output power and optical signal to noise ratio (OSNRs) of the proposed fiber laser are between -0.8 and -2.5 dBm and 59.1 and 61.0 dB/0.06 nm, respectively. The power and wavelength stabilities of the proposed laser are also studied. In addition, the proposed laser can be directly modulated at 2.5 Gbit/s quadrature phase shift keying-orthogonal frequency-division multiplexing (QPSK-OFDM) signal and 20-50 km single-mode fiber (SMF) transmissions are achieved within the forward error correction (FEC) limit without dispersion compensation. It could be a cost-effective and promising candidate for the standard-reach and extended-reach wavelength division multiplexed passive optical network (WDM-PON). (C) 2014 Elsevier Inc. All rights reserved.