Integrated optical instrumentation for the diagnostics of parts by embedded or surface attached optical sensors

An optical system, comprising:

• an optical fiber attached to a structure;
• light source means for providing a broadband source light, said source light being launched into said fiber;
• at least one fiber sensor formed within said optical fiber, said sensor providing reflected light substantially at a reflection wavelength and providing transmitted light at all wavelengths other than said reflection wavelength, said reflection wavelength varying in response to a perturbation of said structure near where said sensor is attached;
• integrated tunable opto-acoustic filter means located in the path of output light from said sensor, for filtering said output light received from said sensor, the passband of said filter means being adjustable to overlap with said reflection wavelength of said sensor in response to a filter control signal, and for providing an optically filtered signal having a power related to the optical transmission of said filter at said reflection wavelength of said sensor;
• optical detection means, for detecting the power of said optically filtered signal from said opto-acoustic filter means and for providing a detection signal indicative thereof;
• and
• signal processing means responsive to said detection signal, for providing said filter control signal, for detecting a shift in said reflection wavelength due to said perturbation, and for providing a signal indicative of said perturbation, said signal processing means comprising means including an optical detector responsive to said filter means for outputting an electrical signal, a tracking controller receiving said electrical signal and a reference input signal, an adder connected to an output of said tracking controller and receiving an input offset voltage, and a voltage-controlled oscillator responsive to an output of said coder for controlling said filter means for adjusting said filter control signal for tracking static shifts in said reflection wavelength and for detecting said static shifts and dynamic shifts in said reflection wavelength of said sensor, due to static and dynamic shifts in said perturbation, for a predetermined length of time, and for providing output signals indicative of said static and dynamic shifts in said perturbation.