Wide Temperature Range Distributed Feedback Lasers

Current fiber optic links designed for high dynamic range applications use distributed-feedback (DFB) semiconductor lasers that only operate over a narrow temperature range. Thermoelectric coolers are ordinarily required to maintain the laser within the operating temperature range. This limitation translates into cost, size, complexity and power consumption that are too high for many applications such as phased arrays, wireless communication and broadband communication systems. Today's DFB lasers do not maintain single frequency operation, which is crucial for low noise operation, over a wide temperature range. We propose a program to study Multi-Quantum-Well (MQW) laser which will lead to a wide temperature range DFB laser that will operate from -40 to 85 degrees C without a thermoelectric cooler. The performance capability of a DFB laser rather than a Fabry-Perot laser is needed in high dynamic range applications, especially those that require fiber lengths exceeding a few kilometers. The program objectives include establishing quantum well designs to achieve optical gain characteristics that permit a DFB laser to operate over a wide temperature range, modeling to predict dynamic range performance, and fabrication and measurement of laser structures based on these designs. designs which will lead to a wide temperature range DFB laser that will operate from -40.