| 摘要 |
PURPOSE:To provide the tunable optical filter which is small in size and structure, is widen in a tuning range and is speedy in response time. CONSTITUTION:A substrate 1 is provided with a first clad layer 2 having a first refractive index thereon. Cores 3-1 to 3-4 having the second refractive index larger than the first refractive index are formed on this first clad layer 2. The upper part thereof is coated with a second clad layer 4 having another refractive index to form waveguides. The waveguides are constituted by using glass for the first clad layer 2 and the cores 3 and a high-polymer material for the second clad layer 4. In addition, a heater 7 for heating the waveguides is provided. |
