A solid-state broad-band amplifier of far-infrared radiation (1.5 - 4.2 THz) based on intersubband transitions of hot holes in p-Ge is demonstrated using two p-Ge active crystals, when one operates as an oscillator and one as an amplifier. A peak gain higher than usual for p-Ge lasers has been achieved using time separated excitation of the oscillator and amplifier. Active mode locking of the p-Ge laser has been achieved in the Faraday configuration of electric and magnetic fields with distinct advantages over Voigt geometry. The 200 ps pulses of 80-110 cm-1 radiation were achieved by local gain modulation from an applied rf electric field at the 454 MHz round trip frequency of the laser cavity.
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