Single frequency and tunable laser diodes

The state-of-the-art technologies for single-frequency and frequency-tunable laser diodes are reviewed. Spectral linewidth characteristics for distributed-feedback laser diodes are discussed, based on experimentally observed discrepancies from the theory and improvements obtained with quantum-well active regions. Frequency-tunable mechanisms are reviewed mainly for monolithic tunable laser diodes with distributed-Bragg-reflector (DBR) or distributed-feedback configurations.<
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