| 摘要 |
PURPOSE:To control optical scanning with extremely small electric power by polarizing incident light from the outside by a refractive index distribution corresponding to the density of carriers so as to scan emergent light. CONSTITUTION:The potential of electrodes 1, 3 is equalized with the potential of a GaAs substrate 8, the concn. of carriers in n-GaAs 5 is controlled by an electric field applied to an electrode 2 and a metal-insulator-semiconductor structure having insulating Al0.3Ga0.7As as the insulator is formed. When an element is produced so that the density of carriers in the n-GaAs 5 is regulated to 1X10<19> [cm<-3>] and negative voltage is applied to the electrode 2, a depletion layer is formed under the electrode 2 and the concn. of carriers lowers. As a result, the refractive index rises and a region having a higher refractive index is formed only just under the electrode 2. Light incident on the n-GaAs 5 is polarized by the formed region. Optical scanning is enabled with extremely small electric power by changing the refractive index by an electric field so as to carry out optical scanning and an extremely small-sized scanning light source having a high quality single mode can be obtd.
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