Patent ID: 6490080
Filing Date: 2002-12-03
Classification: H01S,H04B

Abstract:
An optical signal converting apparatus for converting an input optical signal to an electrical signal, comprising:a photodetector having an input signal port and an output signal port; an optical amplifier optically coupled to the input signal port of said photodetector, said optical amplifier optically amplifying the input optical signal and outputting an optically amplified signal to the input signal port of said photodetector; a pump optically coupled to said optical amplifier, said pump injecting pumping light into said optical amplifier to provide the optical amplification of the input signal; a power measuring device optically communicating with said optical amplifier, said power measuring device outputting power measurements indicative of the amplified signal's optical power received by said photodetector; and a controller operatively connected to said pump and to said power measuring device; said controller receiving the power measurements from said power measuring device; said controller commanding a pump power level output by said pump to perform gain control according to the power measurements received from said power measuring device; said optical amplifier including: a circulator having a first port, a second port, and a third port, wherein the first port of said circulator receives the input optical signal and outputs the received input optical signal to the second port of said circulator; an erbium doped fiber optically communicating with the second port of said circulator; a coupler optically communicating with said erbium doped fiber; an optical selector optically communicating with said coupler; and an optical termination optically communicating with said optical selector; and said pump optically communicating with said coupler, said pump injecting the pumping light into said erbium doped fiber via said coupler.