Patent ID: 7537395

Claim:
An optical coupling method for modular apparatus, the method comprising: providing an enclosure, wherein the enclosure has a first external port and a second external port; providing a first delivery fiber connected to the first port; providing a first gain fiber, wherein a first end of the first gain fiber is connected to the delivery fiber, wherein the first gain fiber is outside the enclosure; and within the enclosure: generating laser light from a plurality of laser diodes that are within the enclosure; collimating light from the plurality of laser diodes into a collimated pump-light beam, wherein the pump light in the collimated pump-light beam has a characteristic first wavelength; directing pump light inside the enclosure from the collimated pump-light beam to exit the enclosure via the first external port such that the pump light propagates through the delivery fiber to the first gain fiber, and wherein the directing of pump light inside the enclosure includes wavelength-selective transmitting the collimated pump-light beam towards the first port; receiving signal light coming from the first gain fiber outside the enclosure through the delivery fiber and through the first external port, wherein the signal light has a characteristic second wavelength different than the first wavelength; and directing signal light inside the enclosure between the first external port and the second external port such that light derived from the signal light exits the enclosure via the second external port, wherein the directing of signal light inside the enclosure includes wavelength-selective reflecting of signal light from the first port towards the second port.