Scanning multichannel spectrometry using a charge-coupled device (CCD) in time-delay integration (TDI) mode

A spectrometer using a CCD array in the time-delay integration mode, comprising

• a CCD array having a plurality of photosensitive charged-coupled devices disposed along a scan dimension which terminates at an output end of said CCD array, each of said devices producing an electronic charge in response to electromagnetic radiation incident thereon;
• a scanning monochromator, optically aligned with said CCD array, having a dispersing optical element which generates a plurality of spectral beams from a source of electromagnetic radiation, the plurality of spectral beams being emitted substantially along respective scan planes, the dispersing optical element being movably mounted to sequentially scan said plurality of spectral beams;
• a control unit, coupled to said monochromator, which controls the scanning operation of said dispersing optical element and determines a scan rate for the spectral beams, the scan plane of each of the spectral beams being oriented at a substantially right angle to the scan dimension of said CCD array such that the spectral beams are scanned along said scan dimension during the scanning operation, the charge-coupled devices of said CCD array producing electronic charge in amounts proportional to the intensity of the spectral beams;
• a first clock source, coupled to said CCD array, which sequentially shifts the electronic charge from one charge-coupled device to another along the scan dimension of said CCD array at a shift rate substantially equal to the scan rate of said spectral beams;
• a serial shift register, coupled to the output end of said CCD array, which accumulates the electronic charge as it is shifted to the output end of said CCD array;
• a second clock source, coupled to said serial shift register, which sequentially shifts the electronic charge in said serial register to an output node;
• and
• an output amplifier, coupled to the output node of said shift register, which receives the electronic charge from said shift register and produces a video signal therefrom,
• whereby a plurality of video signals is produced in response to the scanning of said plurality of spectral beams across said CCD array, said video signals representing intensity values of said plurality of spectral beams respectively.

An apparatus for resolving and detecting spectra, comprising

• a CCD array having a plurality of photosensitive charge-coupled devices disposed along a scan dimension which terminates at an output end of said array, each of said devices producing an electric charge in response to electromagnetic radiation incident thereon;
• means, optically aligned with said CCD array, for generating a plurality of spectral beams from a source of electromagnetic radiation, said plurality of spectral beams being emitted substantially along respective scan planes;
• means for adjusting the relative position of said plurality of spectral beams and said CCD array at an adjustment rate, the scan plane of each spectral beam being oriented substantially at a right angle to the scan dimension during said adjusting function, the charge-coupled devices of said CCD array producing electric charge in amounts proportional to the intensity of the spectral beams;
• means, coupled to said CCD array, for shifting the electric charge from one charge-coupled device to another along the scan dimension of said array at a shift rate substantially equal to the adjustment rate of said adjustment means;
• and
• means, coupled to the output end of said CCD array, for accumulating the electric charge as it is shifted to the output end of said array and producing a video signal therefrom,
• whereby a plurality of video signals is produced in response to the relative position adjustment of said plurality of spectral beams and said CCD array, said video signals representing intensity values of said plurality of spectral beams respectively.

A method for resolving and detecting spectra, comprising the steps of

• generating a plurality of spectral beams from a source of electromagnetic radiation, said plurality of spectral beams being dispersed substantially along respective scan planes;
• adjusting the relative position of said plurality of spectral beams and a CCD array at an adjustment rate, the scan plane of each spectral beam being oriented substantially at a right angle to the scan dimension during said adjusting step, said CCD array having a plurality of charge-coupled devices disposed along the scan dimension, said charge-coupled devices producing electric charge in amounts proportional to the intensity of the spectral beams;
• sequentially shifting the electric charge from one charge-coupled device to another along the scan dimension of said CCD array at a shift rate substantially equal to the adjustment rate;
• and
• accumulating the electric charge as it is shifted to the output end of said CCD array and producing a video signal therefrom,
• whereby a plurality of video signals is produced in response to the relative position adjustment of said plurality of spectral beams and said CCD array, said video signals representing intensity values of said plurality of spectral beams respectively.