Abstract

Superluminescent Diodes (SLD's) are the key element in certain fiber optic sensors such as fiber gyroscopes [l-33]. The broad-band characteristics of SLD's reduce the noise due to Rayleigh backscattering, polarization noise, and bias offset due to the nonlinear Kerr effect in fiber optic sensor system. Therefore, there is a need for a high power, high efficiency SLD which emits into a stable, single spatial mode for such applications. The optimal approach to design a SLD is to base on a proven high power, high efficiency "window" type buried heterostructure laser which is capable of emitting greater than 50 mW CW into a stable index-guided lateral mode. Lasing is suppressed for SLD operation by antireflection (AR) coating the emitting facet and by incorporating a rear absorber section. The resulting device emits high optical power 22.5 mW in the SLD mode at very low injection current 100 mA. The spectral modulation depth is below 25% over the entire emission spectral bandwidth of 20 nm, with a symmetrical beam divergence (20°×40°) and a stable transverse mode.

© 1988 Optical Society of America