| 摘要 |
PROBLEM TO BE SOLVED: To decrease the leak of speaking between channels and to prevent the operation of an optical assembly from being degraded by providing a filter layer for coating an optical component to absorb stray light. SOLUTION: On a platform 12 of an optical assembly 10, active and passive optical components are supported. The optical components include a laser 14, photodetector 16, turn mirror 18 and plural passive optical waveguides 20. The laser 14 generates the source beam of a wavelength λ1 . The photodetector detects the beam of a wavelength λ2 . The turn mirror 18 couples the passing beam of a wavelength λ3 and the beam of the wavelength λ1 and makes it incident to the optical waveguide 20. The photodetector 16 is coated with a filter layer 22. It is preferable that the filter layer 22 contains a two-component adhesive material containing a light absorbing material in black or dark color. The filter layer 22 can contain the carbon black absorbing material of natural vulcanized silicone for absorbing the light of all the wavelengths. |
