INFLUENCE OF ELECTRIC-FIELD ON THE TRANSMISSION SPECTRUM OF A GASE CRYSTAL

Electroabsorption and photoconductivity spectra of GaSe crystals have been investigated experimentally. The absorption edge shifted towards longer wavelengths by 16 nm under an applied electric field as low as 1 kV/cm. At longer wavelengths, the photosensitivity of samples was ra ised by increasing the applied voltage. A continuous He-Ne laser light (Lambda = 632.8 nm) and dye laser pulses in the range 594-643 nm coul d be modulated up to 100% intensity by a 16 V applied voltage. The red shift is much higher than that evaluated on the base of a Franz-Keldy sh mechanism and have a thermal origin.