Abstract:
The invention provides an optical analysis system for efficient compensation of spectroscopic broadband background, such as spectroscopic fluorescence background or background signals that are due to the dark current of a detector. The optical analysis system effectively provides multivariate optical analysis of a spectroscopic signal. It provides wavelength selective detection of various spectral components that are indicative of a superposition of spectroscopic peaks or bands and their broadband background. Additionally, the optical analysis system is adapted to acquire spectral components that predominantly correspond to the broadband background of the spectroscopic peaks or bands. Wavelength selective selection of various spectral components is performed on the basis of reconfigurable multivariate optical elements or on the basis of a position displacement of a spatial optical transmission mask.
Abstract:
An optical spectrum analyzer (FIG. 2) is provided with a user selectable sensitivity (160). Required operating parameters (172, 174, 176) are set in response to user selection of sensitivity (162) to permit measurement of an input light beam (12) at the selected sensitivity (160). Setting the required parameters (172, 174, 176) includes setting a required gain (172) of a video channel (48, 90, 92, 94, 96) to permit measurement of a specified maximum input signal and to provide the selected sensitivity (160), setting a required video bandwidth (174) of the video channel (48, 90, 92, 94, 96) to provide the selected sensitivity (160) at the required gain (172) of the video channel (48, 90, 92, 94, 96) and setting a sweep rate (176) to provide the selected sensitivity (160) at the required video bandwidth (174). When the normal bandwidth of the video channel (48, 90, 92, 94, 96) is not adequate to provide the selected sensitivity (160), the electrical signal is passed through a digital filter (100) having a filter coefficient (FILTER COEFFICIENT) set to provide the required video bandwidth (174). A peak detector (90) is incorporated in the video channel (48, 90, 92, 94, 96) to accurately measure signal amplitudes in a fast scanning condition.