Kimchau N. Nguyen

Integrated hybrid Si/InGaAs 50 Gb/s DQPSK receiver

A monolithic 25 Gbaud DQPSK receiver based on delay interferometers and balanced detection has been designed and fabricated on the hybrid Si/InGaAs platform. The integrated 30 µm long InGaAs p-i-n photodetectors have a responsivity of 0.64 A/W at 1550 nm and a 3dB bandwidth higher than 25 GHz. The delay interferometer shows a delay time of 39.2 ps and an extinction ratio higher than 20 dB. The demodulation of a 25 Gb/s DPSK signal by a single branch of the receiver demonstrates its correct working principle.

Cascadability properties of MZI-SOA-based all-optical 3R regenerators for RZ-DPSK signals

We experimentally demonstrate 50 cascaded all-optical 3R regenerators over a 1,000 km transmission distance for 10-Gb/s return-to-zero differential phase-shift keying (RZ-DPSK) signals. The regenerator consists of integrated Mach-Zehnder interferometer (MZI) semiconductor optical amplifier (SOA) based wavelength converters. Regenerative properties and tolerance to pattern dependent effects have been studied in terms of Q-factor measurement, and error free operation with input OSNR of 20 dB/0.1 nm has also been demonstrated.

All-optical 2R regeneration of BPSK and QPSK data using a 90° optical hybrid and integrated SOA-MZI wavelength converter pairs

We demonstrate all-optical 2R regeneration with a 90° optical hybrid and integrated MZI-SOA pairs for 10 Gb/s BPSK and 20 Gb/s QPSK with negative power penalty. Power penalty and OSNR improvements of 7 dB and 5 dB are shown with additive ASE noise.

Monolithically integrated dual-quadrature receiver on InP with 30 nm tunable local oscillator

We demonstrate a monolithically integrated dual-quadrature coherent receiver with greater than 30 nm widely-tunable SG-DBR local oscillator, signal input SOAs, a 90° optical hybrid and four 10 GHz photodetectors. With 20 Gb/s NRZ-QPSK, we demonstrate a required OSNR of 10 dB for a BER of 10(-3) at four different wavelengths.

25 Gbaud DQPSK receiver integrated on the hybrid silicon platform

A monolithic 25 Gbaud DQPSK receiver based on delay interferometers and balanced detection was fabricated on hybrid silicon platform. We report preliminary results regarding the characterization of the InGaAs p-i-n photodetectors and the delay interferometer.

Synchronous Optical Packet Buffers

Synchronous optical packet buffering is presented as a solution for asynchronous time division multiplexed (TDM) optical packet switched networks. Truly asynchronous optical packet synchronization and buffering are demonstrated using multiple independent transmitters, synchronous optical buffers, and a burst mode receiver. Optical packet synchronizers are used to dynamically align incoming asynchronous packets to local timeslots for synchronous loading of buffers. Multiple optical buffers based on integrated InP technology resolve contention of packets destined for the same output port at the same time. TDM asynchronous optical packets are detected on a per packet basis using a burst mode receiver with better than 99.9% packet recovery. An analysis of power consumption of the synchronous buffers is presented and potential power reductions are discussed.

Monolithically integrated dual-channel coherent receiver with widely tunable local oscillator for 100 Gbps dual-polarization quadrature phase shift keying applications.

We report implementation of a monolithically integrated 100 Gbps dual-polarization quadrature phase shift keying (DP-QPSK) wavelength tunable coherent receiver on a 1  mm×3  mm die that consists of a tunable C-Band local oscillator with a 40 nm range, eight 30 GHz photodetectors, and two parallel 90° optical hybrids. A BER of 10(-3) with an OSNR of 7.5 dB operating at 50 Gbps NRZ-QPSK data per channel is reported.

Homodyne dual-quadrature coherent receiver with injection-locked monolithically integrated local oscillator

We demonstrate a homodyne dual-quadrature coherent receiver using a monolithically integrated, injection-locked local oscillator. For BER of 10-3 and 10-5, the required OSNR is improved by 1.5 dB and 5 dB, respectively, compared to a free-running local oscillator.

40 Gb/s buffered 2×2 optical packet switching using photonic integrated circuits

Contention resolution and forwarding of labeled optical packets at 40 Gb/s is demonstrated utilizing multiple InP based optical buffers and monolithic wavelength converters. Layer-2 packet recovery measurements are presented.