Yikai Su

Tunable fiber optic parametric oscillator

We report operation of a tunable optical parametric oscillator that employs a nonlinear-fiber Sagnac interferometer as a parametric amplifier. The amplifier, which consists primarily of dispersion-shifted fiber that has zero dispersion at 1538 nm, is synchronously pumped with 7.7-ps pulses at 1539 nm. The wide bandwidth of the parametric gain permits tuning of the output signal pulses over a 40-nm range centered on the pump wavelength. The Sagnac interferometer decouples the pump wave from the oscillator cavity while a bandpass filter in the cavity transmits only the signal wave, thereby creating a singly resonant parametric oscillator that is phase insensitive. Whereas we demonstrate tuning over almost the entire bandwidth of Er-doped-fiber amplifiers, one could construct a similar device that operates near the 1310-nm zero-dispersion wavelength of standard telecommunication fiber.

Wavelength-tunable all-optical clock recovery using a fiber-optic parametric oscillator

Abstract We report a wavelength-tunable clock recovery scheme for all-optical 3R regeneration and simultaneous wavelength conversion. The scheme is based on a fiber-optic parametric oscillator, in which dynamic gain results from the four-wave mixing process in the fiber. In our implementation, 2.9 ps clock pulses are recovered from the incident pseudo-random data stream with the clock wavelength being tunable over the whole erbium-doped-fiber-amplifier bandwidth. RF spectrum measurements show that the recovered clock has less timing jitter than the incident data stream. We also present a two-channel clock recovery experiment, which demonstrates the feasibility of our scheme at 100 Gbit/s data rate.

Polarization insensitive widely tunable all-optical clock recovery based on AM mode-locking of a fiber ring laser

All-optical clock recovery based on injection mode locking of a fiber ring laser is demonstrated by utilizing a fast semiconductor saturable absorber. The recovered clock is jitter free and completely insensitive to the state of polarization of the injection signal. Moreover, the clock wavelength can be tuned over the whole gain bandwidth of the EDFA.

All-optical picosecond-pulse packet buffer based on four-wave mixing loading and intracavity soliton control

We report an all-optical packet buffer that is based on four-wave mixing loading and intracavity soliton pulse control. The target data packet consisting of picosecond pulses is loaded into the storage-buffer cavity by means of four-wave mixing with the pump pulses and stored at the corresponding idler wavelength. We stabilize the timing and amplitude of the stored idler pulses by applying intracavity all-optical soliton control. This is accomplished by combining the synchronous parametric-gain modulation achieved inside a pulse-pumped nonlinear-optical-loop mirror with the intensity discrimination provided by a nonlinear-amplifying-loop mirror. A 20 Gbit/s-packet pattern is loaded and stored for up to several seconds, corresponding to millions of circulations of the packet within the buffer.

Simultaneous 3R regeneration and wavelength conversion using a fiber-parametric limiting amplifier

We present a 3R regenerator with simultaneous functionality of wavelength conversion. It consists of a fiber-parametric limiting amplifier and a phase-locked loop in a novel configuration. The 10 Gbit/s regenerator effectively reduces input signal noise and jitter.

All-optical erasable storage buffer based on parametric nonlinearity in fiber

We present an erasable all-optical buffer based on parametric gain and cross-phase modulation loading. The buffer is erased by employing a loop-mirror as a switch. We demonstrate storage of 1Gb/s packets for 1 ms.

Synchronously mode-locked fiber laser based on parametric gain modulation and soliton shaping

A novel synchronously mode-locked fiber laser is demonstrated by combining the parametric gain modulation in a pulse-pumped nonlinear optical loop mirror (NOLM) with the soliton shaping property of a nonlinear amplifying loop mirror (NALM). Parametric gain modulation induced by the synchronous pump pulses within the NOLM starts and defines the timing of the mode-locked signal pulses, while the nonlinear intensity discrimination in the NALM stabilizes the mode-locked pulses and optimizes their shapes. A stream of 1.3 ps transform-limited soliton pulses is generated when the NOLM is pumped by a mode-locked fiber laser. Moreover, we find that the timing jitter of the synchronously mode-locked pulse train is suppressed by more than 10 dB when compared to the pumping laser.

All-optical storage of picosecond pulse packets using wavelength-induced XPM and parametric amplification

We present phase-insensitive loading of external data in an all-optical storage line wherein linear loss is compensated by phase-sensitive parametric amplification. Storage is achieved for about 100 circulations within the fiber buffer.

Photon statistics of a single mode of spontaneous Raman scattering in a distributed Raman amplifier

Experimental measurement of spontaneous noise statistics from a distributed Raman amplifier has been achieved with single-mode and single-photon resolution. The results agree with quantum theoretical predictions of a Bose-Einstein probability distribution. Distributed Raman amplification is becoming increasingly important in todays optical communication systems. It improves the optical signal-to-noise ratio by providing optical gain inside the transmission fiber.

All-optical laser synchronization and clock recovery based on dynamic parametric gain modulation

A novel all-optical scheme for laser synchronization and clock recovery is demonstrated by combining the parametric gain modulation in a pulse-pumped nonlinear loop mirror with soliton shaping in a nonlinear amplifying loop mirror.