Phase demodulator, optical fiber sound pressure demodulation system, demodulation method and manufacturing method

A technology of phase demodulator and demodulation system, which is applied in the field of sound pressure measurement devices, achieves the effects of high stability, simple structure, and reduced complexity and difficulty

Inactive Publication Date: 2016-11-23
THE HONG KONG POLYTECHNIC UNIV SHENZHEN RES INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the embodiments of the present invention is to provide a phase demodulator

Method used

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  • Phase demodulator, optical fiber sound pressure demodulation system, demodulation method and manufacturing method
  • Phase demodulator, optical fiber sound pressure demodulation system, demodulation method and manufacturing method
  • Phase demodulator, optical fiber sound pressure demodulation system, demodulation method and manufacturing method

Examples

Experimental program
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Example Embodiment

[0037] Example one

[0038] figure 1 It is a structural block diagram of the phase demodulator 10 provided by an embodiment of the present invention, and the details are as follows:

[0039] A phase demodulator 10 adopts the structure of a Sagnac optical fiber ring, is connected with a diaphragm type optical fiber sound pressure sensor 20, includes a broadband light source 101, a photodetector 102, is connected to the photodetector 102, and receives the photodetector 102 The signal analysis module for demodulating the output electrical signal is characterized in that the phase demodulator 10 further includes:

[0040] Connect the broadband light source 101 and the photodetector 102 respectively, and split the light emitted by the broadband light source 101 into a first fiber coupler 103 that transmits CW light clockwise and CCW light counterclockwise;

[0041] Connect the first fiber coupler 103 to adjust the intensity of the CW light, or a tunable optical attenuator 104 that adjusts...

Example Embodiment

[0082] Example two

[0083] image 3 It is a schematic diagram of a preferable structure of the phase demodulator 10 provided by the embodiment of the present invention, and the details are as follows:

[0084] The a port of the first optical fiber coupler 103 is connected to the broadband light source 101, the b port is connected to the photodetector 102, the c port is connected to the first end of the optical fiber delay line 104, and the d port is connected to the tunable light The first end of the attenuator 105;

[0085] The 1 port of the second optical fiber coupler 106 is connected to the second end of the optical fiber delay line 104, the 2 port is connected to the second end of the tunable optical attenuator 105, and the 3 port is the idle end for anti-reflection processing. , The 4-port is connected to the first end of the optical fiber optical frequency shifter;

[0086] The second end of the optical fiber optical frequency shifter is connected to the first end of the opt...

Example Embodiment

[0090] Example three

[0091] Figure 4 It is the structural block diagram of the optical fiber sound pressure demodulation system provided by the embodiment of the present invention, and the details are as follows:

[0092] An optical fiber is used to connect the phase demodulator 10 and a diaphragm optical fiber sound pressure sensor 20 based on a graphene diaphragm.

[0093] Wherein, the diaphragm type optical fiber sound pressure sensor 20 is connected to the phase demodulator 10 by an optical fiber, and reflects light through the graphene diaphragm.

[0094] Figure 5 It is a schematic structural diagram of an optical fiber sound pressure demodulation system provided by an embodiment of the present invention.

[0095] Image 6 It is an implementation flowchart of a demodulation method based on an optical fiber sound pressure demodulation system provided by an embodiment of the present invention. The details are as follows:

[0096] S601: Connect the diaphragm-type optical fiber sou...

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Abstract

The invention, which is suitable for the technical field of the sound pressure measurement device, provides a phase demodulator, an optical fiber sound pressure demodulation system, a demodulation method and a manufacturing method. The phase demodulator employing a Sagnac fiber loop structure comprises a broadband light source, a photoelectric detector, a signal analysis module connected with the photoelectric detector, a first optical fiber coupler connected with the broadband light source and the photoelectric detector, a tunable optical attenuator, a fiber delay line connected with the first optical fiber coupler, a second optical fiber coupler, an optical frequency shifter, and a fiber depolarization device. The tunable optical attenuator connected with the first optical fiber coupler is used for adjusting the intensity of CW light or adjusting the intensity of CCW light; the second optical fiber coupler connected with the fiber delay line and the tunable optical attenuator is used for realizing coupling of light reflected by a membrane type optical fiber sound pressure sensor; the optical frequency shifter connected with the second optical fiber coupler provides stable pi/2 quadrature phase biasing; and the fiber depolarization device connected with the optical frequency shifter is connected with the membrane type optical fiber sound pressure sensor externally by a fiber. According to the invention, stable phase demodulation of the membrane type optical fiber sound pressure sensor is realized.

Description

technical field [0001] The invention belongs to the technical field of sound pressure measuring devices, and in particular relates to a phase demodulator, an optical fiber sound pressure demodulation system, a demodulation method and a manufacturing method. Background technique [0002] Most of the existing sound pressure demodulation systems use optical fiber Fabry-Perot sensors with simple structure and accurate detection to measure sound pressure, usually including a Fabry-Perot cavity composed of an optical fiber end face and a diaphragm end face. When the air pressure acts on the elastic diaphragm, the diaphragm deforms, thereby changing the cavity length of the Fabry-Perot cavity. By detecting the change of the reflected light interference phase difference caused by the change of the cavity length, the sound pressure measurement can be realized. [0003] However, the existing phase demodulator increases the complexity and difficulty of the sensor demodulation system, a...

Claims

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Application Information

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IPC IPC(8): G01H9/00
Inventor 靳伟马军
Owner THE HONG KONG POLYTECHNIC UNIV SHENZHEN RES INST
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