Cavity length dependence of optical characteristics in high power narrow stripe GaAs superluminescent diodes

A high-power planar structure GaAs superluminescent diode (SLD) with a 5- mu m-wide partially current injected region with a 30-200- mu m cavity length has been developed by using a simple wafer process of spin-on-glass Zn selective diffusion. Drastic changes in optical characteristics from the light emitting diode mode to the SLD mode have been observed with increasing cavity length, reflecting the gain of the SLD mode. Experimental results of the far-field patterns, the maximum power output, and the optical spectrum show that the best suited cavity length should be designed carefully depending on the object of practical use.>