Distributed feedback laser diode and module for CATV systems

Harmonic distortion of distributed feedback laser diodes (DFB-LDs) for analog transmission systems is investigated. It is shown that, under a modulation frequency of less than 1 GHz, the harmonic distortion depends on the nonlinearity of the light output power-current (P-I) curve under the continuous wave (CW) condition, which is determined by the coupling constant kappa L, and that the distortion can be minimized at kappa L approximately 1. A 1.3 mu m wavelength InGaAsP DFB-PPIBH (p-substrate partially inverted buried heterostructure) LD and its module, with low distortion by the control of a coupling constant, have been developed.<
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