CN107911782B

CN107911782B - Optical fiber microphone probe and optical fiber microphone system

Info

Publication number: CN107911782B
Application number: CN201711134181.7A
Authority: CN
Inventors: 周瑜; 王坤博; 魏晓村; 刘超; 马宁
Original assignee: Third Research Institute Of China Electronics Technology Group Corp
Current assignee: Third Research Institute Of China Electronics Technology Group Corp
Priority date: 2017-11-16
Filing date: 2017-11-16
Publication date: 2020-04-07
Anticipated expiration: 2037-11-16
Also published as: CN107911782A

Abstract

The embodiment of the invention provides an optical fiber microphone probe and an optical fiber transmissionThe acoustic system is made of SiO-containing material₂The diaphragm of the composition adopts a corrugated structure, releases the stress of the diaphragm and increases the elastic coefficient of the diaphragm, improves the sensitivity and enlarges the frequency response range on the premise of not reducing the resonance frequency, and solves the problem that the existing optical fiber microphone probe cannot realize higher sensitivity and wider frequency response at the same time.

Description

Optical fiber microphone probe and optical fiber microphone system

Technical Field

The invention relates to the technical field of acoustics, in particular to a fiber microphone probe and a fiber microphone system.

Background

The optical fiber microphone as a novel microphone has the advantages of high sensitivity, strong anti-electromagnetic interference capability, low transmission loss, long transmission distance and the like. The higher sensitivity can improve the action distance of the acoustic signal detection and identification system; the anti-electromagnetic interference capability enables the target detection system to be used in special environments such as strong radiation, high temperature and high humidity, can be applied to remote target detection in complex terrain environments, and has great application potential in the fields of transformer detection, gas pipeline monitoring, border early warning monitoring and the like.

The vibrating diaphragm used by the traditional electric microphone probe is mostly a plane metal diaphragm, and the size of the diaphragm affects the sensitivity and the frequency response characteristic simultaneously. The larger the size of the diaphragm is, the higher the sensitivity is, and the narrower the frequency response range is caused; the smaller the diaphragm size, the wider the frequency response range, and the lower the sensitivity. Therefore, it is difficult for the conventional electric microphone to simultaneously achieve high sensitivity and wide frequency response. If the optical fiber microphone probe is directly developed by adopting the metal film, on one hand, the problem that high sensitivity and wide frequency response cannot be realized simultaneously exists, and on the other hand, due to the use of the metal film, a metal material is introduced into the optical fiber microphone probe, so that a sensitive end is easily influenced by high-humidity corrosion and the like; if the nonmetal diaphragm without the corrugated structure is adopted, the problem that high sensitivity and wide frequency response cannot be realized simultaneously exists.

The existing optical fiber microphone mostly adopts a plane diaphragm without a corrugated structure, and the material of the plane diaphragm is mostly metal, silicon, polymer and the like, so that the sensitivity and the frequency response range of the existing optical fiber microphone are difficult to achieve a better state at the same time.

Disclosure of Invention

In a first aspect, embodiments of the present invention provide a fiber optic microphone probe, which is intended to solve the above problems of the existing fiber optic microphone.

The embodiment of the invention provides a fiber microphone probe, which comprises: the optical fiber module comprises a diaphragm, an optical fiber, a shell and a reflecting film, wherein the diaphragm is arranged inside the shell, the reflecting film is arranged on the diaphragm, one end of the optical fiber is arranged inside the shell and has a certain distance with the diaphragm, the other end of the optical fiber is arranged outside the shell, and the diaphragm is made of SiO-containing material₂And the membrane has a corrugated structure.

Preferably, the membrane is square.

Preferably, the reflective film is disposed at the center of the diaphragm.

Preferably, the number of optical fibers is one, wherein the optical fibers serve as both input and output optical fibers.

Preferably, the number of the optical fibers is two, wherein one optical fiber is used for inputting incident light, and the other optical fiber is used for outputting reflected light.

Preferably, the material of the reflecting film is gold.

Preferably, the SiO-containing₂The composition further comprises Si₃N₄。

Preferably, the corrugated structure of the diaphragm is a non-planar structure with the surface of the diaphragm being corrugated.

In a second aspect, an embodiment of the present invention provides a fiber optic microphone system, which further includes the fiber optic microphone probe described in the first aspect.

The optical fiber microphone probe and the optical fiber microphone system provided by the embodiment of the invention adopt the material containing SiO₂Film of the compositionThe diaphragm adopts a corrugated structure, the stress of the diaphragm is released, the elastic coefficient of the diaphragm is increased, the sensitivity is improved and the frequency response range is enlarged on the premise that the resonant frequency is not reduced, and the problem that the existing optical fiber microphone probe cannot realize higher sensitivity and wider frequency response at the same time is solved.

Drawings

Fig. 1 is a schematic plan view of a first fiber optic microphone probe according to an embodiment of the present invention;

fig. 2 is a schematic plan view of a second fiber optic microphone probe according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of the structure of a fiber optic microphone system employing an F-P interference type fiber optic microphone probe;

fig. 4 (a) is a top view of a diaphragm of a fiber optic microphone according to an embodiment of the present invention;

fig. 4 (b) is a cross-sectional view of a diaphragm of a fiber optic microphone according to an embodiment of the present invention.

Detailed Description

Fig. 1 is a schematic plan view of a first fiber optic microphone probe according to an embodiment of the present invention.

In one example, as shown in fig. 1, the fiber optic microphone probe is an intensity type fiber optic microphone probe comprising: a diaphragm 4, an optical fiber 1, an optical fiber 2, a housing 3 and a reflective film 12 (not shown), wherein the diaphragm 4 is disposed inside the housing 3, the reflective film 12 is disposed on the diaphragm, one end of the optical fiber 1 and the optical fiber 2 is disposed inside the housing 3 and spaced from the diaphragm 4, the other end of the optical fiber 1 and the optical fiber 2 is disposed outside the housing 3, the diaphragm 4 is made of a material containing SiO₂And has a corrugated structure.

In one example, the membrane 4 is square, but may have other shapes.

In one example, the reflective film 12 is disposed at the center of the diaphragm 4, but may be disposed at other positions of the diaphragm 4.

In one example, fiber 1 is used to input incident light and fiber 2 is used to output reflected light.

In one example, the reflective film 12 is made of gold, such as platinum or gold, or other materials with high reflectivity and low oxidation resistance.

In one example, SiO is contained₂The composition further comprises Si₃N₄。

In one example, the corrugated structure of the diaphragm 4 is a non-planar structure with the diaphragm surface being corrugated.

Wherein, the membrane 4 is developed by adopting a micro-electro-mechanical processing technology, and a plurality of ripples are processed on the surface of the membrane. The superposition of the corrugated structure releases the stress of the membrane 4 on one hand, so that the degree of influence of the external temperature on the performance of the membrane 4 is greatly reduced; on the other hand, the elastic coefficient of the diaphragm 4 is increased, and the mechanical sensitivity is improved by at least one order of magnitude while higher resonance frequency is ensured.

In the design process, the depth, the width, the corrugation distance and the corrugation number of the corrugated structure are selected in an optimized mode, and the mechanical sensitivity and the resonant frequency can be adjusted flexibly. In order to reduce the hardness of the corrugated diaphragm, it is preferable to use a low-stress SiO-containing film₂The composition (can also be other low-stress semiconductor materials) and the processing of the low-stress membrane is realized by controlling the process flow and the process parameters. The probe of the optical fiber microphone is made of materials containing SiO₂The diaphragm of the composition combines a plurality of ripples processed on the surface of the diaphragm, thereby achieving the effects of simultaneously improving the sensitivity and expanding the wide frequency response range.

The optical fiber microphone comprises two optical fibers, namely an optical fiber 1 and an optical fiber 2, wherein the optical fiber 1 is used for inputting incident light, and the optical fiber 2 is used for outputting reflected light.

Fig. 2 is a schematic plan view of a second fiber optic microphone probe according to an embodiment of the present invention.

As shown in fig. 2, the fiber optic microphone probe is a Fabry-Perot (F-P) interference type fiber optic microphone probe. Compared with fig. 2, the microphone probe has only one optical fiber 11, and the optical fiber 11 serves as both an input optical fiber and an output optical fiber.

Fig. 3 is a schematic structural diagram of a fiber optic microphone system using an F-P interference type fiber optic microphone probe. As can be seen from fig. 3, the fiber optic microphone system includes: diaphragm 4, light source 5, coupler 6, photodetector 7, amplifier 8, signal processor 9, display 10 and sound 13. The working principle and the flow of the optical fiber microphone are as follows:

the light emitted by the built-in light source 5 is transmitted to the optical fiber 11 through the coupler, the optical fiber 11 receives the light and then transmits the light to the reflecting film 12 in the diaphragm 4, the diaphragm 4 modulates the power of the reflected light, the light is reflected to the coupler 6 through the optical fiber 11 again for coupling, the coupled light signal is transmitted to the photoelectric detector 6, the input light and the reflected light interfere in the same optical fiber to form a periodic spectrum signal, meanwhile, the sound signal acts on the diaphragm 4, the diaphragm 4 vibrates to cause the central wavelength of an interference spectrum to shift, the light signal is amplified through the amplifier 8, the offset of the wavelength of the spectrum is detected through the signal processor 9, the light signal is converted into the sound signal, and finally, the sound information is obtained through the display 10 or the sound 13.

The embodiment of the invention provides a fiber microphone probe, which comprises: the optical fiber comprises a diaphragm, a shell, an optical fiber and a reflecting film, wherein the diaphragm is arranged inside the shell, the reflecting film is arranged on the diaphragm, one end of the optical fiber and the diaphragm form a certain distance, the other end of the optical fiber is arranged outside the shell, and the optical fiber is made of materials containing SiO₂The diaphragm of the composition reduces the hardness of the diaphragm, and the diaphragm adopts a corrugated structure, so that the stress of the diaphragm is released, the elastic coefficient of the diaphragm is increased, and the sensitivity and the frequency response range are improved and enlarged on the premise of not reducing the resonance frequency.

The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made on the basis of the technical solutions of the present invention should be included in the scope of the present invention.

Claims

1. A fiber optic microphone probe, comprising: a diaphragm, an optical fiber, a housing and a reflective film, wherein the diaphragm is arranged inside the housing, the reflective film is arranged on the diaphragm, one end of the optical fiber is arranged inside the housing and is arranged at a certain distance from the diaphragm, the other end of the optical fiber is arranged outside the housing,

the membrane is made of SiO-containing material₂The composition of (A), the composition containing SiO₂The composition further comprises Si₃N₄，

The diaphragm is provided with a corrugated structure, the corrugated structure of the diaphragm is a non-planar structure with corrugations machined on the surface of the diaphragm, the corrugations are of a plurality of rectangular groove structures, and the corrugated structure is not arranged at the center of the diaphragm.

2. The fiber optic microphone probe of claim 1, wherein the diaphragm is square.

3. The fiber optic microphone probe of claim 1, wherein the reflective film is disposed in a center of the diaphragm.

4. The fiber optic microphone probe of claim 1, wherein the number of the optical fibers is one, wherein the optical fibers function as both input and output optical fibers.

5. The fiber optic microphone probe of claim 1, wherein the number of the optical fibers is two, wherein one optical fiber is for inputting incident light and the other optical fiber is for outputting reflected light.

6. The fiber optic microphone probe of claim 1, wherein the reflective film is made of gold.

7. A fiber optic microphone system characterized in that the fiber optic microphone system further comprises a fiber optic microphone probe according to any of claims 1-6.