Patent ID: 7391560
Filing Date: 2008-06-24
Classification: H01S,H04B

Abstract:
1. A multistage optical amplifier comprising: a plurality of optical amplifiers in a multistage connection, wherein a first pumping light of a former-stage optical amplifier is incident from a direction of an input signal and a second pumping light of a latter-stage optical amplifier is incident from a reverse direction of the input signal; probe light sources inputting probe lights disposed at both ends of a wavelength range of a main signal to each of said plurality of optical amplifiers, wherein probe lights of the former-stage optical amplifier are incident from a direction of an input signal and probe lights of the latter-stage optical amplifier are incident from a reverse direction of the input signal; and a common control section commonly controlling pumping light powers of said plurality of optical amplifiers, wherein said common control section includes: