Patent ID: 7212555

Claim:
A wavelength locker for determining the wavelength of light emitted by a laser diode, the wavelength locker comprising: a structure including a surface that receives light from a back facet of a laser diode and redirects at least a first portion of the light; a collimating lens supported by the structure including the surface, wherein the collimating lens receives the at least a first portion of the light from the surface; a filter layer supported by the collimating lens that comprises a first filter, wherein the filter layer receives collimated light from the lens; a first photosensitive area supported by the filter layer that receives filtered light through the first filter and detects a first signal; a second photosensitive area supported by the filter layer that receives light that does not pass through the first filter and detects a second signal; and a common substrate, wherein the surface, the collimating lens, the filter layer, the first photosensitive area, and the second photosensitive area are supported by the common substrate; wherein a detection response of the first photosensitive area and a detection response of the second photosensitive area are used to determine the wavelength and power of the light emitted by the laser diode.