Patent ID: 6621958
Filing Date: 2003-09-16
Classification: G01J,G02B,H04B,H04J

Abstract:
A WDM comprising:a structure extending longitudinally from one end to another for supporting components of the WDM; at least two optical components supported at the one end of the structure for transmitting and receiving optical signals; a diffraction grating supported at the other end of the structure-for diffracting the optical signals from the optical components; a lens assembly supported by the structure and disposed between the optical components and the diffraction grating, the lens having a focal length for focusing the optical signals in relation to the optical components; wherein the diffraction grating has an angular dispersion that changes with temperature, and the product of the focal length and angular dispersion remains substantially constant with temperature; and wherein a coefficient of thermal expansion of the structure and the change in index of refraction with temperature of the lens are values selected so that the length of the structure changes proportionally with the focal length of the lens in response to temperature changes in the structure and lens, whereby the lens remains substantially focused in relation to the optical components.