Patent ID: 6075632
Filing Date: 2000-06-13
Classification: G01J,H04B

Abstract:
An apparatus for monitoring optical noise power within a series of predefined wavelength regions, comprising:a series of multi-pass filters arranged on an optically transmissive member, each multi-pass filter in the series including,an optical filter element transmissive to optical energy at wavelengths within a passband including a corresponding one of the predefined wavelength regions in the series of predefined wavelength regions, and reflective to optical energy at wavelengths outside the passband, cascading optical energy outside the passband of each of the optical filters to successive multi-pass filters in the series,multiple optically reflective surfaces directing optical energy within the passband through multiple passes through the optical filter element, selectively transmitting through the optical filter element optical energy at wavelengths within the corresponding one of the predefined wavelength regions; anda series of detectors, each detector in the series receiving the selectively transmitted optical energy from a corresponding one of the multi-pass filters and producing an output signal responsive to the optical power within the predefined wavelength region.