Patent ID: 6836578
Filing Date: 2004-12-28
Classification: G01D,G01K,G01N,G02B

Abstract:
An optical sensor diagnostic system, comprising:a tunable VCSEL incorporating an integrated MEMS wavelength tuner that provides wavelength-tunable light in response to a tuning control signal; an optical waveguide optically coupled to said VCSEL, said tunable light being launched into said optical waveguide; at least one optical sensor disposed in the path of said tunable light, said tunable VCSEL individually illuminating said sensor, said sensor providing a transmitted light having altered amplitude and/or phase at least over some wavelengths within the transmitted wavelength range, said spectral distribution of said altered amplitude and/or phase being responsive to an environmental stimulus; an optical reference path to be optically compared with the sensing path; an optical detector, disposed in the path of said transmitted light, for detecting said transmitted light from said sensor and the optical reference path and for providing an electrical detection signal indicative of the power of said transmitted light throughout the appropriate wavelength range; a controller coupled to said tunable VCSEL, said controller providing a variable tuning control signal to said tunable VCSEL indicative of the desired wavelength of said tunable light; a capacitive or optical reference that determines the wavelength of the light emitted by said tunable VCSEL as a function of time and providing feedback; and a signal processor responsive to said electrical detection signal, for detecting a wavelength defined on the characteristic transmission amplitude feature in order to quantitatively detect the effect on said sensor due to said environmental stimulus, for detecting changes in said wavelength at the characteristic transmission amplitude feature caused by changes in said environmental stimulus, and for providing a signal indicative of said stimulus or change therein for said sensor.