Abstract

The surface-emitting semiconductor laser^1-3 is expected to be a key component in future optoelectronic and optical signal processing applications. Several designs are under development including electrically excited and photopumped lasers. The requirement of a surface-emitting geometry imposes important constraints on laser design, which must be considered to achieve an efficient emitter. For example, the method of extracting the laser beam must accommodate that part of the structure providing electrical excitation. Also, a model that calculates laser properties only at threshold is clearly not adequate. We have developed a transfer equation model of short cavity DFB and DBR surface-emitting lasers in which the resonator is defined by multilayer quarter-wavelength semiconductor structures providing distributed feedback. These lasers naturally lend themselves to a description in which the forward and backward waves are propagated from layer to layer by a set of equations detailing the gain and loss due to the material and the feedback and radiation loss due to the Bragg grating. We apply this method to calculate power output, longitudinal modes, and axial intensity profiles for several laser types. In particular, we show that the forward to backward power ratio can depend on mode number as well as pumping level.

© 1988 Optical Society of America