| 摘要 |
PCT No. PCT/DE87/00322 Sec. 371 Date Feb. 19, 1988 Sec. 102(e) Date Feb. 19, 1988 PCT Filed Jul. 17, 1987 PCT Pub. No. WO88/00778 PCT Pub. Date Jan. 28, 1988.Superheterodyne receivers for optical signals can be composed of two branches. The first branch contains a superheterodyne receiver in which the reception signal and the signal of a local oscillator are mixed in a traditional way; in the second receiver branch, the signal of the local oscillator experiences a 90 DEG phase rotation before the mixing. An optical triple coupler inventively serves for dividing the reception light and the light of the local laser onto both reception branches. This triple coupler can be manufactured as a triple fiber coupler or, on the other hand, has an integrated-optical triple coupler of lithium niobate, glass or of a III-V semiconductor. |
