| 摘要 |
PURPOSE:To improve the reliability by obtaining a bulk effect element by forming a gallium-aluminum-arsenic layer of high resistance and thin gallium-arsenic crystal operating layer on a gallium-arsenic crystal substrate in photoconductive structure. CONSTITUTION:While semiconductor laser 11 having an output at the side of a wavelength longer than one mum is used as a light source, output light 12 is focused by focusing means 13 and then incident to bulk effect element 14, constituted in a photoconductive path shape, from its flank. Bulk effect element 14, made of Ga-As single crystal 15 as a substrate, has operating layer 17 made of a Ga-As layer via clad layer 16 made of a Ga-Al-As layer of low refractive index grown on the substrate, in addition to cathode and anode electrodes 18' and 18'' for bias voltage application at both ends and trigger electrode 18 for inputting external signals near the cathode, thereby permitting this element to provide planar operation. The laser light is modulated and then its transmitted light 19 is converted via lens 20 into a parallel luminous flux, which can be led out by polarizer 21. |
