Generation of frequency modulated laser pulses in a cylindrical semiconductor structure with a travelling space charge wave

The propagation of a slow surface electromagnetic wave of the whispering gallery mode type formed on the surface of a semiconductor cylindrical waveguide is considered. The dynamic of interaction of circularly propagating electromagnetic radiation at wavelength 1.55 μm with an alternating drift current wave in the bulk of a semiconductor is studied. It is assumed that the drift velocity of charge carriers coincides with the speed of circular surface wave which moves along the axis of a cylindrical waveguide. In this case, it is possible to achieve strong phase modulation of a slow surface wave over a wide range of wavelengths so as, the modulated radiation can be converted into a sequence of short pulses. The peak power of the generated pulses is shown to be orders of a magnitude higher than the average pump power. The length of the optical waveguide at which wave packets are formed is determined by the depth and frequency of light modulation in the semiconductor cylindrical waveguide.