Patent attributes
A spectrum analyzer providing an integrated calibration function and for providing that calibration function automatically. The injection of light to be analyzed through a central aperture of a scanning grating onto a focusing reflector provides in combination four traversals of the space therebetween. The spectrometer thus is used to separate wavelength information spacially and receive it back at the same or adjacent aperture(s) to be analyzed by a processing system to establish the spectra for the incident light. The light is typically injected from and received back into optical fibers or other light carrying elements. Calibration light is also applied through the same or adjacent apertures in the grating from a known source and spectra such as Argon to use as a calibration reference by detecting the known spectra peaks and correlating it to grating scan angle. The same structure is also used as a telecommunications channel router by injecting light of multi-channel and thus broadband spectral content into the spectrometer through the central aperture(s) and angling the grating so that a selected channel or channels are reflected back after four passages of the spectral separator to output one or more optical fibers or other guides.