Micro-cantilever beam fiber grating micro-displacement sensor based on quantum enhancement

Abstract

The invention discloses a micro-cantilever beam fiber grating micro-displacement sensor based on quantum enhancement. The micro-cantilever beam fiber grating micro-displacement sensor comprises a laser, a 2*1 coupler, a filter, an erbium-doped fiber amplifier, a filter, a fiber polarization controller, a fiber polarization beam splitter, a dispersion displacement fiber, a coarse wavelength division multiplexer, a fiber isolator, a fiber Bragg grating, a micro-cantilever beam, a balance detector and a spectrum analyzer. According to the invention, quantum entangled double light beams generated after four-wave frequency mixing are used, the quantum entangled double light beams have high quantum correlation, the intensity difference quantum noise of each mode is reduced, the detection light and the reference light quantum correlation noise are subtracted to generate a noise substrate lower than the shot noise limit, so that signals annihilated under the quantum noise can be detected, and thus, ultra-high sensitivity measurement of micro-displacement breaking through the quantum noise limit is achieved. The micro-cantilever beam fiber grating micro-displacement sensor has the advantages of high sensitivity, safety, reliability and the high practical value.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing, in particular to a micro-cantilever fiber grating micro-displacement sensor based on quantum enhancement. Background technique [0002] Fiber Bragg grating micro-displacement sensor uses the principle that the fiber Bragg grating will change the central wavelength under the condition of external strain change, resulting in the change of reflected light intensity to measure the displacement. And because it has the following advantages: 1) Anti-electromagnetic interference, difficult to corrode; 2) Signals propagate through light waves, and the speed is fast; 3) Reusable, which can greatly improve the utilization rate of optical fibers; 4) Small size, plastic shape . Therefore, fiber grating micro-displacement sensors are widely used in structural detection in civil engineering fields, such as large structures such as bridges, dams, power facilities, and offshore oil platforms. [0...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the problem that ordinary fiber grating micro-displacement sensors are limited by wavelength sensitivity and resolution, so that the measurement accuracy cannot be further improved, the present invention proposes a breakthrough quantum noise sensor with extremely high sensitivity, simple structure and high practical value. The ultimate quantum-enhanced micro-cantilever fiber grating micro-displacement sensor

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