Method and apparatus for reducing temperature-related spectrum shifts in optical devices

The present invention discloses a novel technique for reducing the temperature-related spectrum shifts in optical devices, particularly waveguide grating routers. In general, the present invention modifies a portion of the length of at least one waveguide within an optical device in a manner that stabilizes the wavelength spectrum passing therethough even when exposed to temperature variations. More specifically, by knowing how the refractive index of a certain material changes with temperature variations as compared to that of common waveguide materials, such as silica, one may employ the teachings of the present invention to precisely modify the nature of the optical path through which a signal travels to fully compensate for any temperature-related wavelength spectrum shift. As shown, a portion of both cladding (16) as well as core material (14) has been replaced with elastomeric material (20). Furthermore, an additional step may be included whereby the portion of the elastomeric material (20) adjacent the upper cladding (16) is etched away and replaced with more cladding material.