MEASUREMENT OF OPTICAL-MODE LOSS IN VISIBLE EMITTING LASERS

We describe a technique for direct measurement of the passive optical mode loss of a semiconductor laser or similar semiconductor waveguide structure, based upon measurement of the attenuation of optically exci ted luminescence in the guided mode as a function of distance traveled along the passive guide. A spectrometer is used to select luminescenc e in the low energy tail of the spectrum which is subject to very litt le reabsorption. We have applied the method to a series of highly stra ined GaInP quantum well laser structures and observe an increase in th e mode loss from 9.9 cm(-1) for 1% strain to 46 cm(-1) for 1.7% strain . This correlates with the appearance of clustered regions in the high ly strained wells observed by transmission electron microscopy (TEM). (C) 1997 American Institute of Physics.