Patent ID: 9184554
Filing Date: 2015-11-10
Classification: H01S

Abstract:
1. An apparatus for reducing a thermal dependence of gain of an optical amplifier, the apparatus comprising: an input port for inputting an input optical beam; a variable beam splitter optically coupled to the input port and configured for splitting the input optical beam into first and second sub-beams, the variable beam splitter having a power splitting ratio dependent on temperature; first and second optical paths for propagating the first and second sub-beams, respectively, the first and second optical paths having an optical path length difference therebetween; a beam combiner coupled to the first and second optical paths, for combining the first and second sub-beams propagated through the first and second optical paths, respectively, into an output optical beam, wherein a coupling efficiency of the first and second sub-beams into the output optical beam has a wavelength dependence due to the optical path length difference; and an output port optically coupled to the beam combiner for outputting the output optical beam; wherein an amplitude of the wavelength dependence is dependent on the power splitting ratio and thereby has a dependence on the temperature, wherein in operation, the thermal dependence of gain of the optical amplifier is lessened by the dependence of the amplitude on the temperature.