Optical magnetic field sensing system for generating resonance frequency band by using piezoelectric ceramics

Abstract

The invention discloses an optical magnetic field sensing system for generating a resonance frequency band by using piezoelectric ceramics, which is characterized in that a transmitting end of a tunable laser, an attenuator, a polarization controller, a polarization controller and an optical fiber taper are connected in sequence, and the optical fiber taper and the magnetic field sensing system are coupled together through evanescent waves at a taper area of the optical fiber taper; light coupled into the magnetic field sensing system is coupled out through an optical fiber taper and then is sent to a photoelectric detector, alternating current / direct current signals are separated out through a T-shaped bias device, and the alternating current / direct current signals are respectively sent to an oscilloscope for display, an electric spectrometer and a network analyzer for display and sent to a PID control box for outputting wavelength of a laser; and the piezoelectric ceramic generates a resonance frequency band by generating ultrasonic waves with the frequency between the resonance frequencies of two mechanical modes of the hollow pipe cavity, the defect that the system sensitivity fluctuates greatly along with the change of the detection frequency due to the fact that the line width is too narrow is overcome, and the piezoelectric ceramic-based ultrasonic transducer has the advantages of being small in size, high in integration degree, low in loss, low in power consumption and resistant to electromagnetic interference.

Description

technical field [0001] The invention relates to an optical magnetic field sensing system that uses piezoelectric ceramics to generate resonance frequency bands, specifically relates to an optical magnetic field sensing system constructed of piezoelectric ceramics, magnetostrictive media and optical resonant cavities, and belongs to the field of optics. Background technique [0002] Magnetic field sensors are widely used in digital economy, transportation, life and health, national defense and other fields, and they can be realized in various ways. Compared with the existing magnetic field sensing methods, the magnetic field sensing technology based on the optical system has the advantages of fast speed and strong anti-electromagnetic interference ability. Whispering gallery is a type of cavity that has been explored more in recent years. It mainly uses the principle of total internal reflection of light. When the qualified light reaches the phase coherent superposition condi...

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Problems solved by technology

However, due to the extremely narrow frequency spectrum line width of the mechanical mode, when the scheme is applied to the sensing system, if there is a certain distance between the frequency of the AC magnetic field to be measured and the frequency of the mechanical mode, the detection sensitivity of the system will be reduced , so that the application of the device is limited

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