| 摘要 |
PURPOSE:To obtain a stable output by amplifying optical signal with a stable gain without being affected by ambient temperature and wavelength of input optical signal. CONSTITUTION:Output light of a rare earth doped optical fiber 1 is extracted by an optical divider 5, a filter 8, and a photodiode 7 and converted into electric signals. An obtained electric signal is converted into a dc signal by a preamplifier 9 and an integrator 10, and the level of this dc signal is compared with a preset reference level which a reference power source 12 generates by a comparator 11. A drive circuit 13 receives a result of comparison from the comparator 1 and adjusts the luminous amount of a laser diode 3, that is, the magnitude of excitation laser light. |
