Siao-Shan Jyu

A 110 GHz passive mode-locked fiber laser based on a nonlinear silicon-micro-ring-resonator

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).

250-GHz Passive Harmonic Mode-Locked Er-Doped Fiber Laser by Dissipative Four-Wave Mixing With Silicon-Based Micro-Ring

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.

S-band pulse generation by polarization additive-pulse mode-locking in an erbium-doped all-fiber ring laser

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.

Asynchronous Harmonic Mode Locking in an All-Normal Dispersion Yb-Doped Fiber Laser

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.

Multi-bound pulse state in a 250 GHz mode-locked fiber laser based on a silicon micro-ring resonator

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.

Laser dynamics of asynchronous mode-locked fiber lasers

New laser dynamics of asynchronous mode-locked fiber lasers will be reviewed in details, with the emphases on the interesting repetition frequency pulling effect and the all-normal dispersion operation state of asynchronous mode-locking.

Asynchronous rational harmonic mode-locked fiber laser and in-situ determination of its effective modulation strength

Based on the laser dynamics of asynchronous mode-locking, we have developed a new method for in-situ determining the effective modulation strength in asynchronous rational harmonic mode-locked Er-doped fiber lasers up to 33 GHz repetition rate.

A new dispersioin measurement apparatus by a periodic wavelengh-scanning pulse laser

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.