INFLUENCE OF SPATIALLY INHOMOGENEOUS GAIN SATURATION, CAUSED BY A STANDING-WAVE, ON THE AMPLITUDE-FREQUENCY MODULATION CHARACTERISTIC OF SEMICONDUCTOR-LASER RADIATION

The framework of linearised laser equations for the field and charge c arriers is used to obtain an analytic expression which describes the m odulation response function of a semiconductor laser and takes account of spatially inhomogeneous gain saturation caused by a standing wave. Account is also taken of spatial variations of the carrier density al ong the cavity axis, which appear because of different rates of stimul ated recombination near the standing-wave nodes and antinodes, and bec ause of 'expulsion' of free carriers from the wave antinodes by electr ostriction forces. It is shown that the influence of the standing wave leads to a change in the response function near a resonant frequency f(0) and has a minor effect on the value of this function at frequenci es exceeding f(0). Therefore, this influence has practically no effect on the maximum modulation frequency f(m) of a semiconductor laser.