| 摘要 |
PROBLEM TO BE SOLVED: To make the power of an output light (wavelength multiplex light) constant through maximum constant control using only one wave having maximum power and to make respective channels nearly equal in level. SOLUTION: An optical level control means 24 which controls the optical level of the propagated wavelength multiplexed light is provided, part of the wavelength multiplexed light outputted by the optical level control means 24 is made to branch off, and a variable wavelength optical filter 13 selectively outputs respective wavelength lights included in the wavelength multiplexed light. Then a photoelectric converting means 14 photoelectrically converts the respective wavelength lights outputted by the variable wavelength filter and a peak value detecting means detects the maximum peak value of the electric signal outputted by the photoelectric converting means and inputs a feedback signal to the optical level control means 24 so that the maximum peak value reaches a set value. |
