Gregory A. Fish

High performance widely-tunable SG-DBR lasers

Widely-tunable sampled-grating distributed Bragg reflector (SG-DBR) lasers with integrated Semiconductor Optical Amplifiers (SOAs) simultaneously exhibit high (20 mW CW) fiber-coupled output power, high side mode suppression ratio, low noise (below -140 dB/Hz RIN), low line-width (<5 MHz), and high reliability, across a 40 nm C-band tuning range.

Monolithically integrated widely tunable 40Gbits/s wavelength converter with optical label modulation function

What we believe to be a novel monolithically integrated wavelength converter consisting of a sampled grating distributed Bragg reflector laser, a long semiconductor optical amplifier (SOA), and a delayed interferometer Mach-Zehnder interferometer (DIMZI) is reported. Error-free 40Gbits/s wavelength conversion for three different probe wavelengths is demonstrated. The impact of the output filter bandwidth and filter detuning on the performance of wavelength conversion is studied in detail. The optical label modulation of the on-chip DI-MZI is first demonstrated with amplitude- and phase-shift key schemes.

InP chip scale integration platform for high performance tunable lasers

Tunable semiconductor lasers have been listed in numerous critical technology lists for future optical communication systems. Lasers with full band tuning ranges (C or L) allow reduction of the inventory cost and simplify deployment and operation of existing systems in addition to enabling wavelength agile networking concepts in future systems. Furthermore, monolithic integration of full band tunable lasers with modulators to form complete transmitters offers the most potential for reducing system size, weight, power consumption, and cost. This paper summarizes design, fabrication technology, and performance characteristics of widely tunable CW sources and transmitters based on chip scale integration of a Sampled Grating Distributed Bragg Reflector (SG DBR) laser with a Semiconductor Optical Amplifier (SOA) and Electroabsorption (EA) or Mach Zehnder (MZ) modulator. Widely tunable CW sources based on SG-DBR lasers exhibit high fiber coupled output power (20 mW CW) and side mode suppression ratio (>40 dB), low relative intensity noise (below -140 dB/Hz) and line width (<5 MHz) across a 40 nm C-band tuning range. Characteristics of EA-modulated optical transmitters include fiber-coupled time-averaged powers in excess of 5 dBm, RF extinction ratios > 10 dB, and error-free transmission over 350 km of standard fiber at 2.5 Gb/s across a 40 nm tuning range. Monolithic integration of widely tunable lasers with MZ modulators allow for further extension of bit rate (10 Gb/s and beyond) and transmission distances through precise control of the transient chirp of the transmitter. Systematic investigations of accelerated aging confirm that reliability of these widely-tunable transmitters is sufficient for system deployment.

Multielectrode tunable lasers

While tunable lasers have been a focus of research and development efforts for over 10 years, they have only recently gained market acceptance in optical transport and networking. Tunable lasers offer many compelling advantages over fixed wavelength solutions in optical networks in that they reduce inventories, allow dynamic wavelength provisioning, and simplify network control software. More interesting, is that tunable lasers have been featured in optical network development efforts in every segment: access/enterprise, metropolitan, and long haul networks leading to a variety of desired specifications and approaches. In fact, the term tunable laser has come to describe an increasingly broad range of technologies from monolithic semiconductor lasers, to MEMS (Micro-Electro-Mechanical Systems) based lasers and fiber lasers. This presentation will focus on monolithic, widely-tunable lasers which are promising candidates to satisfy the needs of all the market segments mentioned.

Demonstration of Simultaneous Multiplexing/Demultiplexing Operation of an All-Optical 2x2 Packet Switch with Asynchronous Variable-length Optically Labeled 40Gbps Packets

We demonstrate simultaneous multiplexing/demultiplexing operation of a 2x2 all-optical packet switch loaded with a random iMix stream of asynchronous variable-length 40Gbps optically-labelled packets. Layer-2 performance shows ≫ 95% optical label and ≫ 90% packet throughput for both ports.