A novel scheme to detect optical DPSK signals

We propose and demonstrate a novel approach to detect optical differential phase-shift keying signals. The technique is based on differential phase-to-polarization conversion in a polarization-maintaining fiber, so that the polarization-modulated signal can be detected by using a polarizer and a common intensity modulation receiver

All-Optical Clock Recovery for NRZ-DPSK Signals

We experimentally demonstrate an optical clock recovery scheme for nonreturn-to-zero differential phase shifting keying (NRZ-DPSK) data. By using an optical circuit made by a proper fiber Bragg filter and a Fabry-Pérot based clock extraction circuit, we obtain a stable and low jitter 10-GHz optical clock signal. This signal shows comparable performance with the original electrical clock in bit-error-rate measurements and oscilloscope triggering operation

Single and Multicast Wavelength Conversion at 40 Gb/s by means of Fast Nonlinear-Polarization-Switching in an SOA

We experimentally demonstrate all-optical wavelength conversion of a 40-Gb/s nonreturn-to-zero signal by means of nonlinear polarization switching in a single semiconductor optical amplifier (SOA). Using a highly nonlinear SOA optimized for very fast gain recovery time, we observe no appreciable penalty for the conventional (single) wavelength conversion. We also obtain, for the first time by using this technique, the simultaneous multiconversion to different wavelengths (four on a 200-GHz frequency grid) of an input signa

"WDM-DPSK Detection by means of Frequency-Periodic Gaussian Filtering"

A single frequency-periodic narrow filter converts DPSK to intensity modulation in a high number of WDM channels. It also strongly enhances their tolerance to chromatic dispersion and is exploited in a 16x10 Gbit/s transmission over 240 km G.652 fibre with no chromatic dispersion compensation

Preamplified Demodulation of 56-Gb/s WDM-DPSK Signals by an AWG-Based InP PIC

A compact preamplified receiver for wavelength division multiplexed-diffferential phase shift keying (WDM-DPSK) signals based on Gaussian filtering is proposed and simulated, and a first implementation, including an semiconductor optical amplifiers (SOA) and an ad-hoc arrayed waveguide grating (AWG), is demonstrated by monolithical integration in an InP platform. The demodulation of 56-Gb/s channels on the eight 100-GHz-spaced AWG outputs is experimentally reported, and simulation results show the feasibility of multiwavelength operation obtaining simultaneous demultiplexing and demodulation of all the channels. The resilience to chromatic dispersion for the Gaussian filter demodulation is also shown by simulations

Photonic Integrated Fully Tunable Comb Generator Cascading Optical Modulators

We report the first monolithic InP photonic integrated comb generator made by cascading optical modulators. The device is extremely compact and tunable both in repetition frequency and wavelength, making real-world applications possible. A distributed Bragg reflector laser, a Mach-Zehnder intensity modulator, and two phase modulators are monolithically integrated on a 4.5 x 2.5 mm(2) chip that also includes a booster semiconductor optical amplifier at the output. Modulators integrated on the circuit have a 3 dB bandwidth of 7 GHz and can generate up to 28 comb lines within a 5 dB power range when properly electrically driven (here demonstrated in the range 4-5 GHz). Operation up to 10 GHz is also reported.This work was supported by the European Commission, FP7 framework through Project 619205-"Access Center for Photonics Innovation Solutions and Technology Support".Publicad