Active mode locking of the far-infrared p-Ge laser is achieved via gain modulation with an rf electric field applied at one end of the crystal parallel to the Voigt-configured magnetic field. A small intrinsic voltage is observed between the rf contacts during lasing which significantly impairs the gain and also the achievable intensity and duration of mode-locked pulses. This voltage is directly compensated by applying a bias to the rf contacts. First results give mode-locked pulse durations of ~200 ps.
© 1998 Optical Society of AmericaPDF Article