Interrogator for a plurality of sensor fiber optic gratings including a driver/modulator
View Patent ↗An interrogator for a plurality of sensor fiber optic gratings. The interrogator includes a broadband optical source; at least one beam splitter directing output of the optical source to the sensor fiber optic gratings; at least one linear filter for converting changes in peak reflection wavelength to changes in intensity; at least one optical receiver; and at least one amplifier associated with each optical receiver. The interrogator also includes, alternatively, a driver/modulator for the optical source providing on/off pulses; an analog integrator following the at least one amplifier; or a mechanism compensating for masking of one sensor fiber optic grating by another.
1. An interrogator for a plurality of sensor fiber optic gratings comprising:
a broadband optical source;
at least one beam splitter directing output of the optical source to the sensor fiber optic gratings;
at least one linear filter for converting changes in peak reflection wavelength to changes in intensity;
at least one optical receiver;
at least one amplifier associated with each optical receiver; and
a driver/modulator for the optical source providing on/off pulses.
2. The interrogator of claim 1 wherein the driver/modulator for the optical source provides randomization of intensity ripple phase versus wavelength.
3. The interrogator of claim 1 wherein an injection current to the optical source is varied sinusoidally.
4. The interrogator of claim 3 wherein the sinusoidal variation is less than 2% and a period in the range of 0.1% to 1% of the sampling interval.
5. The interrogator of claim 1 wherein the broadband optical source is one of a Light Emitting Diode (LED), a Superluminescent Light Emitting Diode (SLED), an Amplified Spontaneous Emission (ASE) source, and a Semiconductor Optical Amplifier (SOA).