| 摘要 |
<p>An input signal of a frequency f0 is supplied to one end of a photodiode (21). Optical signals of frequencies F0 and F0 + DELTA F from two light sources (25, 26) are combined by a semitransparent mirror (27) and the resulting interference light is applied to the photodiode. The interference light is converted by the photodiode to an electrical local signal of a frequency DELTA F. The electrical local signal and the input signal are frequency mixed in accordance with the nonlinear characteristic of the photodiode and an intermediate-frequency signal of a frequency corresponding to the frequency difference between them is provided at an output terminal. <IMAGE></p> |
