TEMPERATURE STABILIZATION OF OPTICAL WAVEGUIDES

A method of temperature stabilizing an optical waveguide having positive thermal optical path length expansion, in particular a stable single polarization mode optical fiber distributed feed back laser or a distributed Bragg reflector optical fiber laser, comprising affixing optical waveguide to at least two points of a composite material having negative thermal expansion; said composite material comprising a resin matrix having embedded therein fibers having a negative thermal expansion coefficient, and optionally fibers having a positive thermal expansion coefficient. Further a method of packaging optical fiber lasers that acts to reduce frequency jitter and hence reduce the spectral linewidth of the laser through damping of thermal fluctuations and acoustic vibrations originating from the environment; said packaging method comprising encapsulating the fiber laser within a curable viscous substance such as silicone or other elastomer.