SBIR-STTR Award

Due to the enhanced differential quantum efficiency, high differential gain and potential low laser relative intensity noise of strained Quantum Well (QW) lasers, there is a significant opportunity to develop fiber optic links that employ QW lasers which may exceed the current link loss and noise figure performance of bulk laser based links. While high speed (>20GHz) strained layer QW lasers operating at short wavelengths have been demonstrated, no QW devices have yet been made that operate above l7GHz at l.3um or l.5um wavelength. This program will investigate the feasibility of developing, packaging and characterizing long wavelength (l.3um and l.5um) 25GHz modulaton bandwidth strained QW lasers for microwave and millimeterwave transmission applications. In particular, the effort will use existing QW material and laser structure models to optimize the modulation bandwidth of lasers that employ innovative InGaAs(P)/InP and InGaAlAs QW material systems. Furthermore, we will evaluate our existing laser packaging up to 25GHz and determine if improvements are required to realize the potential bandwidth of the new laser structure in a commercial microwave fiber optic transmitter/link.

Keywords:
LASER MICROWAVE QUANTUM WELL RADAR MILLIMETER-WAVE FIBER OPTIC

During the SBIR Phase I program "25GHz MQW Laser" Lasertron has demonstrated that Ridge-Waveguide-Strained-Layer-Multi-quantum (SL-MqW) lasers based on a new InGaAlAs material system are capable of operating at >20GHz and has demonstrated the feasibility of these devices working at speeds in excess of 2SGHz. Using this new high performance material system Lasertron has achieved performance with a RWG chip structure which was only previously possible with more complex and inherently less reliable buried heterostructure lasers using the more traditional InGaAsP material. Lasertron has demonstrated a 10 dB improvement in dynamic range and a 10 dB improvement in fiber optic link loss with SL-MQW material as compared to bulk material. In Phase II Lasertron proposes to develop this material system further to produce a robust laser chip capable of operating at 2S5Hz. This will be combined with a package development activity to extend the operating range of the current microwave package beyond 25GHz. The Phase I work showed the module performance is currently package limited to 2OGHz. As part of the program, Lasertron will conduct reliability studies on both the laser chip and microwave module based on the Bellcore TA-T5Y-000983 requirements.