Continuous variation of the emission frequency in pumping lasers with electron beam

A possibility of smooth frequency variation of a laser with electron beam pumping is studied by using crystals of semiconductor-compound solid solutions. In a rectangular crystal of a solid solution composition and the forbidden-band width change along the crystal. Two side faces form mirrors of an optical cavity. When the electron beam moves along the crystal the excitation region displaces and, thus, the generation wavelenth changes. Generation modes of crystals obtained are investigated. The spectra have a distinct exciton structure. Laser generation is realized when Znsub(x)Cdsub(1-x)S crystals are excited at 80 deg K with a nitrogen laser radiation (lambda = 3371 A). As the composition x varies from 0 to 1 in the Znsub(x)Cdsub(1-x)S and Znsub(x)Cdsub(1-x)Se crystals, the generation wavelength changes within the range of 0.33-0.50 μm and 0.46-0.7 μm respectively. The generation threshold in the best samples at 80 deg K lies within 1-3 A/cm2 and increases by a factor of 10 with increasing temperature up to 300 deg K. In Znsub(x)Cdsub(1-x)S samples the maximum range of smooth variation of wavelength makes up 270 A. The maximum value of power for such a sample achieves 200-300 W. It is noted that with further development of the crystal growing method it will be possible to increase considerably the range of smooth variation of frequency