SOLID STATE WIDEBAND FOURIER TRANSFORM INFRARED SPECTROMETER

摘要

A compact, low cost FTIR spectrometer with no moving parts includes an interferometer having optical paths through silicon waveguides. The optical path lengths are varied by changing the temperature and/or carrier density of at least one of the waveguides. In embodiments, the interferometer is a Mach-Zehnder interferometer. Embodiments vary both optical path lengths in opposite directions. In embodiments, a germanium or InGaAs IR detector is grown on the same wafer as the waveguides. Embodiments include a laser pump, such as a COT CW diode laser, and wavelength mixer, such as an OPGaAs or OPGaP converter, for up and/or down converting measured IR wavelengths into a range compatible with the waveguide and detector materials. The wavelength mixer can be a waveguide. Embodiments include a sample compartment and an IR source such as a glowbar. In embodiments, the sample compartment can be exposed to ambient atmosphere for analysis of gases contained therein.

主权项

1. A Fourier Transform Infrared (“FTIR”) Spectrometer, comprising:
a controller; an optical signal input; an optical interferometer configured to receive an FTIR input wave from said optical signal input, said optical interferometer having at least two light paths, each of said light paths being directed through a waveguide comprising a waveguide material, all of said light paths being fixed in physical length, at least one of said light paths being variable in optical length by changing an index of refraction of the waveguide material of the light path under control of said controller; and an infrared detector, configured to receive and detect an output of the optical interferometer.