| 摘要 |
PURPOSE:To impose modulation with superior temperature characteristics through small-sized constitution by providing electrodes which control an optical transmission direction to a llght guide which is made of an electrooptic material and has an Y branch, and coupling an optical fiber with one branch light guide and a semiconductor laser with the other light guide. CONSTITUTION:The light guide 12 which is formed of a perovskite type composite oxide containing lead, titanium, and zirconium and has the Y branch is provided with a couple of electrodes 22a and 22b which control the light transmission direction by voltage impression to constitute an optical modulating element 20. The optical fiber 14 is coupled with one of the branch light guides 21a and 21b, i.e. light guide 21b, and the semiconductor laser 11 is coupled with the other light guide 21c. When a specific voltage is impressed between the electrodes 22a and 22b, the light guide under the electrode gap 23 decreases in refractive index and the guided light l1 of the light guide 21c is reflected totally under the gap 23 and guided as light l2 to the light guide 21b. The light travels straight to the light guide 21a unless the voltage is impressed to obtain guided light l2. Thus, the modulation with superior temperature characteristics is imposed through the small-sized constitution. |
