Design and fabrication of a surface-illuminated-type semiconductor optical modulator with electron-depleting absorption control

Design and test fabrication were carried out for a surface-illuminated-type semiconductor optical modulator with electron-depleting absorption control. In a theoretical design example with optimum conditions, it is expected that the extinction ratio is about 10 dB with a voltage change of -5 V, the insertion loss is less than 1 dB, and the operating speed is several hundred megahertz to several gigahertz. On the other hand, the extinction ratio of a surface-illuminated-type modulator fabricated for a preliminary experiment was about 10 dB with a voltage change of -7.5 V. An optical transmission-type modulator operated at a low driving voltage is realized. (C) 1998 Scripta Technica, Electron Comm Jpn Pt 2, 81(11): 42-53, 1998.