| 摘要 |
<p>An apparatus for sensing an environmental parameter includes an interferometer sensor that detects the environmental parameter. A Mach-Zehnder interferometer is optically coupled to the output of the first interferometer to receive an output signal. The Mach-Zehnder interferometer splits the output signal into first and second optical beams. A phase modulator is disposed in one or both of the optical paths of the Mach-Zehnder interferometer to modulate the phase of the beam. An integrator feedback loop provides a feedback signal to the phase modulator so that the phase modulator cancels phase changes in the optical beam caused by the sensing of the environmental parameter. The feedback signal is proportional to the environmental parameter sensed by the first interferometer. Accordingly, the feedback signal from the integrator feedback loop serves as a unique output signal that is proportional to the parameter to be sensed.</p> |
