| 摘要 |
In a variable wavelength optical filter, a lens (3) is positioned at the output end of a first optical fiber (1) and transforms an input optical signal to parallel light. A dielectric interference optical filter (8) is located at the rear of the lens (3) in order to transmit only the light of particular wavelength. A lens (4) converges the light output from the filter (8) into the input end of a second optical fiber (2). A rotary plate (7) is affixed to the output shaft (6) of a servo motor (5) whose rotation angle is controlled by an electric signal fed from the outside of the filter. The filter (8) is mounted on the rotary plate (7) with the intermediary of a piezoelectric element or elements (9). The piezoelectric elements (9) are caused to oscillate by a modulating signal, so that the transmission center wavelength of the filter is varied. The resulting deviation of the transmission center frequency is detected.
|
