Patent ID: 6549687
Filing Date: 2003-04-15
Classification: G01N,G02B,H01S

Abstract:
An optical sensor diagnostic system, comprising:a tunable VCSEL incorporating an integrated MEMS wavelength tuner for providing wavelength-tunable light in response to a tuning control signal, said tunable light being launched into an optical waveguide, said tunable VCSEL including a movable tuning mirror and a capacitive or optical detector for detecting the position of the movable tuning mirror and providing feedback; at least one optical sensor, disposed in the path of said tunable light, said at least one sensor providing a transmitted light having at least one associated characteristic amplitude feature selected from the group consisting of a minimum, a maximum or a slope located at a particular wavelength within the transmitted wavelength range, said wavelength at each minimum, maximum or sloped transmission amplitude being responsive to an environmental stimulus imposed upon said at least one sensor; said tunable VCSEL individually illuminating said at least one sensor in a wavelength range spanning said wavelength location of said associated characteristic transmission amplitude feature; an optical isolator, disposed in the path of said tunable light between said tunable VCSEL and said at least one sensor, for isolating said tunable light source from light reflected from said at least one sensor; an optical detector, disposed in the path of said transmitted light, for detecting said transmitted light from said at least one sensor and for providing an electrical detection signal indicative of the power of said transmitted light throughout a predetermined wavelength range; a controller for providing a variable tuning control signal to said tunable VCSEL indicative of the desired wavelength of said tunable light; at least one wavelength reference independent of said tuning control signal and moveable mirror position detector disposed in the path of the light; 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 at least one sensor due to said environmental stimulus, 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.