Comparison on crosstalk tolerance of RZ-DPSK and RZ-OOK modulation format in fiber optical parametric amplifier

We investigated crosstalk tolerance of RZ-DPSK and RZ-OOK modulation format in OPA with 100GHz channel spacing. Results show an average of 2.4dB improvement in Q factor by using RZ-DPSK format over RZOOK format.published_or_final_versio

A comprehensive study on crosstalk suppression techniques in fiber optical parametric amplifier by modulation format

With the presence of multiple-WDM input signals, ON-OFF keying (OOK)-modulated signals suffer from crosstalk in fiber optical parametric amplifier (OPA) due to cross-gain modulation (XGM) and four-wave mixing (FWM) effects. We demonstrated substantial crosstalk suppression in one-pump OPA by using return-zero differential phase-shift keying (RZ-DPSK) modulation format, which with its pattern-independent amplitude and subunity duty cycle would be effective in reducing the XGM and FWM effects significantly. By using the RZ-DPSK format, the power penalty was improved by at least 0.8 dB over RZ-OOK, non-RZ (NRZ)-DPSK, and NRZ-OOK formats with four 10 Gb/s channels, separated by 200 GHz spacing. With eight 10 Gb/s channels separated by 100 GHz spacing, a Q -factor penalty of the RZ-DPSK signal was reduced by 2.4 dB compared to RZ-OOK counterparts. © 2008 IEEE.published_or_final_versio

All-optical tunable delay with NRZ-to-RZ format conversion capability based on optical Kerr switch and pulse pre-chirping

All-optical tunable delay plays an important role for enabling high-throughput optical routing, such as buffer for contention resolution and timing synchronization. We proposed and demonstrated a widely tunable optical delay using optical Kerr-switch-based wavelength converter and pulse pre-chirping for compensating chromatic dispersion in fiber delay. With wideband operation provided by a Kerr-switch wavelength converter, a tunable delay range up to 8.56 ns was achieved. Meanwhile, pulse pre-chirping helped to alleviate group-velocity dispersion (GVD)-induced penalty, and provided simultaneous nonreturn-zero (NRZ)-to-RZ format conversion functionality. © 2008 IEEE.published_or_final_versio

Wide-band generation of picosecond pulse using fiber optical parametric amplifier and oscillator

We first demonstrate a wideband generation of picosecond pulse using fiber optical parametric amplifier (FOPA). High quality pulse is generated at 85 nm away from the pump with pulsewidth narrower than that of the pump. We then explore fiber optical parametric oscillator (FOPO) configuration which has the advantage of eliminating the need of seeding laser, leading to a potentially wider wavelength tunability and flexibility. The tuning range of the FOPO is from 1511 nm to 1541 nm and from 1583 nm to 1613 nm, which is as wide as 60 nm, with wavelength span of over 100 nm. Nearly-transform-limited sub-picosecond pulses are generated by this technique. © 2009 IEEE.published_or_final_versio

Ultrawideband doublet pulse generation using optical parametric amplifier

We demonstrated a novel technique to generate ultrawideband doublet pulse using pump depletion and idler generation in optical parametric amplifier (OPA). High quality doublet pulse with repetition rate up to 4.2 GHz was successfully generated.link_to_subscribed_fulltex

80-Gbps to 10-Gbps OTDM De-multiplexer based on wavelength exchange in highly-nonlinear fibre

All-optical 1:8 de-multiplexer for 80Gbps optical time-division multiplexing signals is demonstrated using fibrebased wavelength exchange. Error-free operation is achieved over all de-multiplexed channels with ≤2.1dB power penalty at 10 -9 bit-error rate. © 2008 IEEE.link_to_subscribed_fulltex

Simultaneous optical delay and NRZ-RZ format conversion via cross-polarization modulation and pulse pre-chirping

We demonstrate a tunable optical delay with NRZ-RZ format conversion capability by using cross polarization modulation and pulse pre-chirping. Continuous delay up to 8.6 ns with -1 dB power penalty was achieved using this scheme. © 2008 Optical Society of America.link_to_subscribed_fulltex

Pulsed pump wavelength exchange for high speed signal de-multiplexing

We report the first experimental demonstration of pulsed pump wavelength exchange in a highly nonlinear dispersion-shifted fiber for all-optical time de-multiplexing of 80 Gb/s return-to-zero (RZ) signals. Orthogonal pulsed pump and continuous wave (cw) pump are used in the fiber-based wavelength exchange for ultra-fast power switching. Error-free operation was achieved for the proposed all-optical 1:8 de-multiplexer over all time de-multiplexed 10 Gb/s RZ signals with ≤ 2.1 dB power penalty at 10 -9 bit-error rate. The experimental results show that a wide-band phase-matching is feasible for fiber-based nonlinear parametric processes. ©2008 Optical Society of America.link_to_subscribed_fulltex

Ultra-wideband pulse generation based on cross-gain modulation in fiber optical parametric amplifier

A novel approach to generate ultra-wideband (UWB) monocycle or doublet pulse using cross-gain modulation in fiber optical parametric amplifier is demonstrated in a single experimental setup. The high-speed optical parametric process realizes the signal amplification, idler generation, and pump depletion simultaneously within femtosecond response time in the highly nonlinear fiber. After the combination of the three lightwaves with a suitable time delay between them, UWB pulse is obtained. A selective generation of monocycle or doublet pulse can be made by altering the optical attenuators without changing the wavelengths or the powers of the pump and the signal. In our experiment, high-quality UWB monocycle and doublet pulses with a fractional bandwidth of 115% and 126% were generated. © 2009 IEEE.link_to_subscribed_fulltex

Ultra-wideband pulse generation based on cross-gain modulation in fiber optical parametric amplifier

A novel approach to generate ultra-wideband (UWB) monocycle or doublet pulse using cross-gain modulation in fiber optical parametric amplifier is demonstrated in a single experimental setup. The high-speed optical parametric process realizes the signal amplification, idler generation, and pump depletion simultaneously within femtosecond response time in the highly nonlinear fiber. After the combination of the three lightwaves with a suitable time delay between them, UWB pulse is obtained. A selective generation of monocycle or doublet pulse can be made by altering the optical attenuators without changing the wavelengths or the powers of the pump and the signal. In our experiment, high-quality UWB monocycle and doublet pulses with a fractional bandwidth of 115% and 126% were generated. © 2009 IEEE.link_to_subscribed_fulltex