Patent ID: 7623235

Claim:
A wavelength multiplexer/demultiplexer suitable for analyzing a spectra composition of an optical beam, the wavelength multiplexer/demultiplexer enabling a detection of light of a particular wavelength, the wavelength multiplexer/demultiplexer comprising: an input slit for allowing an entry of the optical beam into a spectrometer, a location of the input slit being adjustable for controlling a performance of the wavelength multiplexer/demultiplexer; an output slit for allowing the exiting of the optical beam, a location of the output slit being adjustable for controlling the performance of the wavelength multiplexer/demultiplexer; and a curved grating for analyzing the spectra composition of the optical beam, the curved grating comprising a plurality of grooves, a distance between the grooves being dependent on the location of the input slit and the output slit, a center of operation wavelength, the diffraction order, a refractive index of the medium and on the location of the adjacent grooves, such that a path difference between two adjacent grooves is an integral of the center of operation wavelength, wherein an arc length of the grooves is the same.