| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a wavelength selective light receiving element in a wavelength multiplex transmission system for generating the same wavelength on both transmission receiving sides, by controlling a relative wavelength with respect to the wavelength of reference light. SOLUTION: A lower reflector 402, a resonator 403, and an upper reflector 404 are laminated on a semiconductor substrate 401. A striped light receiving element 405 is laminated thereon. In this case, a vertical resonance filter is constituted by the lower reflector 402, the resonator 403 and the upper reflector 404. The light receiving element 405 is driven by an upper electrode 406 and an intermediate electrode 407. When a voltage is applied between the intermediate electrode 407 and a lower electrode 408, a refractive index of the resonator 403 is changed, so the resonance wavelength of each vertical resonance filter corresponding to all the light receiving elements 405 can be changed all together. Then, an absolute wavelength can be changed while a space between selective wavelengths of the light receiving element 405 is kept constant.</p> |
