Fiber optic mixer and spectrometer

In an FT-IR spectrometer having a radiation source, an interferometer and a plurality of optical circuits that is optically coupled to an optical switch that in turn is optically coupled to a detector, the improvement comprising:

• an optical fiber mixer having a curved input end portion and a straight output end portion such that any ray entering the input end portion of the optical fiber will have at least one reflection within the optical fiber before exiting from the output end portion of the optical fiber;
• a plurality of optical fibers optically coupled to the output end portion of the optical fiber of said mixer with each of said plurality of optical fibers having a core diameter less than the core diameter of the optical fiber of said mixer and said plurality of optical fibers being optically coupled to the corresponding plurality of optical circuits;
• and,
• means for concentrating the radiation from the interferometer on the input end of said fioer optic mixer.

In an FT-IR spectrometer having a radiation source, an interferometer and a plurality of optical circuits that is optically coupled to an optical switch that in turn is optically coupled to a detector, the improvement comprising:

• an optical fiber mixer having a curved input end portion and a straight output end portion, said curved input end portion having a radius of curvature equal to or greater than 25 times the diameter of the core of the optical fiber mixer;
• a plurality of optical fibers optically coupled to the output end portion of the optical fiber mixer with each of said plurality of optical fibers having a core diameter less than the core diameter of the optical fiber mixer and said plurality of optical fibers being optically coupled to the corresponding plurality of optical circuits;
• and,
• means for concentrating the radiation from the interferometer on the input end of said optical fiber mixer.

In an FT-IR spectrometer having a radiation source, an interferometer and a plurality of optical circuits that is optically coupled to an optical switch that in turn is optically coupled to a detector, the improvement comprising:

• an optical fiber mixer having a curved input end portion and a straight output end portion, said curved input end portion having a curvature such that the average number of reflections in the curved portion of entering radiation is greater than 2;
• a plurality of optical fibers optically coupled to the output end of said optical fiber mixer with each of said plurality of optical fibers having a core diameter less than the core diameter of the optical fiber mixer and said plurality of optical fibers being optically coupled to the corresponding plurality of optical circuits;
• and,
• means for concentrating the radiation from the interferometer on the input end of said optical fiber mixer.