Spectral optic temperature sensor

Claim 1

An optical spectral temperature sensor comprising: means for generating a beam of light of predetermined spectral bandwidth; dispersing means optically disposed to receive said beam of light for dispersing said beam as a function of wavelength to generate a diverging spectrum; a first optically transparent medium; a second optically transparent medium contiguous with said first medium and optically disposed to receive portions of said spectrum at angles of incidence ranging from less than to greater tha a critical angle of incidence determined by the indices of refraction of said first and said second optically transparent media, the index of refraction of at least one of said media being variable as a function of temperature, whereby, those components of said diverging spectrum striking said second optically transparent medium at an angle less than said critical angle are refracted through said second medium and at an angle greater than said critical angle are reflected by said second medium, said refracted and reflected portions of said diverging spectrum being a function of the temperature of at least one of said media; collimating lens means disposed to receive the refracted portion of said diverging spectrum to collimate same; condensing lens means optically disposed to receive said collimated spectrum and form a beam comprising the refracted portion of said spectrum; a first reflecitng surface optically disposed to reflect a predetermined element of sid diverging spectrum directly to said condensing means to define a first reference spectral element; and means for communicating said beam and first reference spectral element to a spectral analyzer.