Compact multi-channel gas correlation sensor and sensing methodology

A multi-channel gas correlation sensor, comprising:

• a pupil-imaging optical system for forming a pupil image of a beam of light energy at a plurality of locations;
• a spectral partitioning filter positioned at one of said locations wherein said beam impinges thereon, said spectral partitioning filter partitioning said beam into a plurality of unique spectral regions wherein each of said spectral regions is confined to a unique spatial region of said beam and passes light energy associated with a unique spectral band;
• beam splitting optics positioned to receive said beam partitioned into said spectral regions, said beam splitting optics generating two beams wherein one of said two beams traverses a first path and another of said two beams traverses a second path, each of said two beams having substantially identical spectral, polarization, and geometric qualities as said beam impinging on said beam splitting optics;
• at least one optically-transmitting gas cell disposed in said first path;
• at least one optically-transmitting gas cell disposed in said second path;
• at least one gas populating at least one said optically-transmitting gas cell, each said gas being disposed in only one of said first path and said second path, each said gas at least partially absorbing said light energy in at least one of said spectral regions;
• and
• a detector positioned at another of said locations to have each of said two beams impinge on a unique and non-overlapped portion of said detector after said one of said two beams traverses said first path and after said another of said two beams traverses said second path.

A method of performing multi-channel gas correlation sensing, comprising the steps of:

• forming a pupil image of a beam of light energy at a plurality of locations;
• spectrally partitioning said beam at one of said locations into a plurality of unique spectral regions, wherein each of said spectral regions is confined to a unique spatial region of said beam and passes light energy associated with a unique spectral band;
• splitting said beam partitioned into said spectral regions to generate two beams, wherein one of said two beams traverses a first path and another of said two beams traverses a second path, each of said two beams having substantially identical spectral, polarization, and geometric qualities as said beam prior to said step of splitting;
• providing at least one gas of interest, each said gas being disposed in only one of said first path and said second path, each said gas at least partially absorbing said light energy in at least one of said spectral regions;
• and
• detecting each of said two beams uniquely at another of said locations after said one of said two beams traverses said first path and after said another of said two beams traverses said second path.