| 摘要 |
PURPOSE:To improve an extinction ratio, a low operating voltage and a high speed modulating characteristics of the titled element by providing a transparent electrode on a plane meeting at a right angle to a direction of a laminated layer, and by substantially coinciding a resonance wavelength of Fabry-Perot resonator with an optical wavelength which shows the max. optical absorption amount on the prescribed impressed voltage value. CONSTITUTION:An N-type GaAlAs film 13 is formed on a substrate made of N-type GaAs, and a super lattice layer 16 and a P-type GaAlAs film 19 are laminated on the film 13 in order, and then removes the N-type GaAs substrate, thereby controlling a thickness of the N-type GaAlAs film 13. The thickness of the N-type GaAlAs film 13 is reduced to control the thickness of the film so as to approach to the max. optical absorption value. The transparent electrode 20 made of a Cr film and an Au film are formed on the P-type GaAlAs film 19, and the electrode 22 made of the Cr film and the Au film are coated on a part of the electrode 20. The transparent electrode 21 made of the Au film is formed on the N-type GaAlAs film 13. The Au-Ge-Ni-alloy film is coated on a part of the electrode 21, and is heated to stabilize the alloy, thereby obtaining the electrode 23. Therefore, the high speed optical modulating element having a high extinction ratio is obtd. |
