A miniaturized laser acoustic field structure and hydrophone

Abstract

The present invention is applicable to the technical field of underwater acoustic detection, and provides a miniaturized laser acoustic field structure and a hydrophone. The miniaturized laser acoustic field structure includes: a reference frame, in which an acoustic inlet channel is provided; a plurality of groups of acoustic and optical sensing components are arranged on the reference frame; each group of the acoustic and optical sensing components includes two acoustic and optical sensors, and the two acoustic and optical sensors are arranged relative to the acoustic inlet channel; the acoustic and optical sensors include a laser emitting unit, an optical path range extension unit, and a laser receiving unit, one end of the optical path range extension unit is connected to the laser emitting unit, and the other end is connected to the laser receiving unit, so that the direction of the laser passing through the acoustic inlet channel is perpendicular to the direction of the laser reflected in the optical path range extension unit. The present invention closely arranges the laser emitting unit, the optical path range extension unit, and the laser receiving unit on the reference frame, which not only ensures the stability of the optical path, but also reduces the volume of the overall structure.

Description

Technical Field

[0001] The invention belongs to the technical field of underwater acoustic detection, and in particular relates to a miniaturized laser acoustic field structure and a hydrophone. Background Art

[0002] Laser Acoustic Field Hydrophone is a device that uses laser technology to detect and measure sound waves in water. It emits a laser beam into the water. When the laser encounters tiny pressure changes caused by sound waves, these changes change the reflection or scattering characteristics of the laser. By analyzing the changes in the returned laser signal, the presence and characteristics of the sound wave can be detected. The laser acoustic field hydrophone relies on a laser to emit a laser beam, which senses the sound signal information and acts on a four-quadrant detector.

[0003] However, existing laser acoustic field hydrophones all use solid-state lasers and four-quadrant detectors, and all components including the laser and the four-quadrant detector are connected together, which makes the laser acoustic field hydrophone complicated to deploy and large in size, making it inconvenient to integrate into small equipment such as underwater AUVs, and inconvenient to perform underwater exploration. Therefore, compared with the existing combined laser acoustic field hydrophone, a laser acoustic field hydrophone with a high degree of integration and lighter weight is urgently needed. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide a miniaturized laser acoustic field structure, aiming to solve the problem of large design volume of laser acoustic field hydrophone.

[0005] The embodiment of the present invention is implemented as follows: a miniaturized laser acoustic field structure, the miniaturized laser acoustic field structure comprising:

[0006] The reference frame has a sound inlet channel extending therethrough;

[0007] A plurality of groups of acoustic and optical sensing components are arranged on the reference frame; each group of the acoustic and optical sensing components includes two acoustic and optical sensors, and the two acoustic and optical sensors are arranged relative to the sound inlet channel; the acoustic and optical sensors include a laser emitting unit, an optical path range extending unit and a laser receiving unit, one end of the optical path range extending unit is connected to the laser emitting unit, and the other end is connected to the laser receiving unit, so that the direction of the laser passing through the sound inlet channel and the direction of the laser reflected in the optical path range extending unit are perpendicular to each other.

[0008] Furthermore, the acoustic-optic sensor also includes a reflection unit, which is arranged on the reference frame and is used to reflect the laser emitted by the laser emitting unit so that the laser enters the optical path range extender unit after passing through the sound inlet channel twice.

[0009] Furthermore, the acoustic and optical sensor also includes a spectroscopic unit, which includes a first spectrometer and a second spectrometer, and the first spectrometer and the second spectrometer are both arranged on one side of the optical path extender unit, so that the laser passes through the first spectrometer and the second spectrometer in sequence, passes through the sound inlet channel back and forth, and then passes through the second spectrometer and the first spectrometer in sequence to enter the optical path extender unit.

[0010] Furthermore, the spectroscopic unit also includes a reflector, and the laser emitting unit and the spectroscopic unit are respectively arranged on two adjacent sides of the optical path extending unit, and the reflector is used to vertically reflect the laser emitted by the laser emitting unit into the first spectrometer and the second spectrometer.

[0011] Furthermore, a plurality of mounting columns are provided on the side of the reference frame, and the acoustic and optical sensors are mounted on two adjacent mounting columns, so that the two acoustic and optical sensors of each group of the acoustic and optical sensing components are parallel to each other.

[0012] Furthermore, the acoustic-optic sensor also includes a mounting plate, which is mounted on two adjacent mounting columns, and the laser emitting unit, the optical path range extender unit and the laser receiving unit are all arranged on the mounting plate, and the direction in which the optical path range extender unit reflects the laser is parallel to the mounting plate.

[0013] Furthermore, the acoustic and optical sensor also includes a mounting plate, which is mounted on two adjacent mounting columns. The laser emitting unit, the optical path extending unit, the laser receiving unit and the spectroscopic unit are all arranged on the mounting plate, and the direction in which the optical path extending unit reflects the laser is parallel to the mounting plate.

[0014] Furthermore, the number of the mounting posts is 4, and the number of the acoustic and optical sensing components is a multiple of 2.

[0015] Furthermore, the miniaturized laser acoustic field structure also includes a shell, and the reference frame and several groups of the acoustic and optical sensing components are arranged in the shell.

[0016] Furthermore, the optical path extension unit includes a module body and two plane reflectors, and the two plane reflectors are arranged in parallel on both sides of the module body, so that the laser incident on the module body is reflected back and forth between the two plane reflectors.

[0017] The present invention also aims at a hydrophone, which comprises a cable, an electronic compartment and the miniaturized laser acoustic field structure, wherein one end of the cable is connected to the acoustic-optical sensor assembly, and the other end is connected to the electronic compartment.

[0018] The embodiment of the present invention provides a miniaturized laser acoustic field structure, in which the laser emitting unit, the optical path range extension unit and the laser receiving unit are closely arranged on a reference frame; the laser emitted by the laser emitting unit enters the optical path range extension unit and is finally received by the laser receiving unit; wherein the optical path range extension unit serves to increase the optical path and increase the sensitivity of optical sensing detection. Since the direction of the laser in the optical path range extension unit is perpendicular to the direction of the laser emitted by the laser emitting unit, this means that the two optical path range extension units of each group of acoustic and optical sensing components are arranged horizontally opposite to each other; compared with the situation where the two optical path range extension units are arranged in a line vertically, this embodiment reduces the volume of the overall structure while ensuring the stability of the optical path. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A three-dimensional diagram of a miniaturized laser acoustic field structure provided by an embodiment of the present invention;

[0020] Figure 2 A top view of a miniaturized laser acoustic field structure provided by an embodiment of the present invention;

[0021] Figure 3 A three-dimensional diagram of an acoustic-optical sensor assembly provided by an embodiment of the present invention;

[0022] Figure 4 A side view of an acoustic-optical sensing assembly provided by an embodiment of the present invention;

[0023] Figure 5 An optical path diagram of the acoustic-optical sensing assembly provided in an embodiment of the present invention;

[0024] Figure 6 A three-dimensional diagram of a hydrophone provided by an embodiment of the present invention;

[0025] 100, reference frame; 110, mounting column;

[0026] 200, acoustic and optical sensor; 210, laser emitting unit; 211, diode laser; 212, collimator; 220, optical path extension unit; 230, laser receiving unit; 240, reflection unit; 250, mounting plate; 260, spectroscopic unit; 261, reflector; 262, first spectrometer; 263, second spectrometer;

[0027] 300, housing;

[0028] 400. Cable. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] Figure 1 and Figure 2 They are respectively a stereoscopic view and a top view of a miniaturized laser acoustic field structure according to the first embodiment, wherein the miniaturized laser acoustic field structure comprises:

[0031] The reference frame 100 has a sound inlet channel extending therethrough;

[0032] A plurality of groups of acoustic-optical sensing components are arranged on the reference frame 100; each group of the acoustic-optical sensing components includes two acoustic-optical sensors 200, and the two acoustic-optical sensors 200 are arranged relative to the sound inlet channel; the acoustic-optical sensor 200 includes a laser emitting unit 210, an optical path range extending unit 220 and a laser receiving unit 230, one end of the optical path range extending unit 220 is connected to the laser emitting unit 210, and the other end is connected to the laser receiving unit 230, and the direction of the laser passing through the sound inlet channel is perpendicular to the direction of the laser reflected in the optical path range extending unit 220.

[0033] In this embodiment, the laser emitted by the laser emitting unit 210 enters the optical path range extending unit 220 and is finally received by the laser receiving unit 230; wherein the optical path range extending unit 220 serves to increase the optical path and increase the sensitivity of optical sensing detection. Since the direction of the laser in the optical path range extending unit 220 is perpendicular to the direction of the laser emitted by the laser emitting unit 210, this means that the two optical path range extending units 220 of each group of acoustic and optical sensing components are arranged horizontally relative to each other; compared with the situation where the two optical path range extending units 220 are arranged in a line vertically, this embodiment reduces the volume of the overall structure while ensuring the stability of the optical path.

[0034] In this embodiment, Figure 3 2 is a three-dimensional diagram of the acoustic-optic sensor assembly of this embodiment. The two acoustic-optic sensors 200 of each acoustic-optic sensor assembly are arranged at intervals so that the propagation direction of the sound wave forms a certain angle with the direction in which the laser passes through the sound inlet channel. The number of acoustic-optic sensor assemblies depends on the actual situation. Several layers can be provided, and each layer can have several groups. Figure 1 The example given is a case where there are two layers and two groups in each layer. This embodiment realizes acoustic signal sensing in different angles and directions by setting the acoustic and optical sensing components in different directions, such as Figure 2 As shown, a laser acoustic field hydrophone array model is formed by two horizontal laser beams to realize the measurement of the horizontal angle of arrival of spatial sound waves; a laser acoustic field hydrophone array model is formed by two vertical laser beams to realize the measurement of the vertical angle of arrival of spatial sound waves; and the wave vector spatial information sensing can be completed by combining the horizontal and vertical angle information.

[0035] In this embodiment, Figure 4It is a side view of the acoustic-optical sensing assembly (the mounting plate 250 is not shown). The laser emitting unit 210 can be a diode laser directly, or a combination of a diode laser 211 and a collimator 212; the function of the collimator 212 is to collimate the light beam emitted by the diode laser 211 to improve the performance of the laser beam. In the past, the laser emitting unit used a solid laser, while the laser emitting unit of this embodiment uses a diode laser, which is compact and easy to install. The laser receiving unit 230 is used to convert the optical signal into an electrical signal to realize the laser sensing of the acoustic wave signal; generally, a four-quadrant detector is selected. It can be understood that as long as it meets the requirements of signal conversion, it can be regarded as the laser receiving unit 230 described in this embodiment. The optical path extension unit 220 includes a module body and two plane reflectors; when the laser beam enters the module body, it will be reflected between the two plane reflectors to increase the optical path, thereby enhancing the sensitivity of the optical sensing detection of the entire system. During the reflection process, the laser beam of the optical path extension unit 220 is in the same plane, and the direction of the laser passing through the sound input channel is perpendicular to the plane; that is, the optical path extension unit 220 is installed horizontally on the reference frame 100, which will reduce the volume of the entire miniaturized laser sound field structure.

[0036] In this embodiment, the propagation direction of the optical path is: the laser emitting unit 210 emits a laser, the laser passes through the sound inlet channel, enters the optical path range extension unit 220, and is finally received by the laser receiving unit 230. This embodiment does not provide a specific setting of the optical splitter. It can be understood that when the propagation direction of the optical path needs to be changed, the optical splitter can be set at a required location to meet the requirements of the above optical path propagation direction.

[0037] In an optimization scheme, if Figure 3 and 4 As shown, the acoustic-optic sensor 200 is optimized. The acoustic-optic sensor 200 further includes a reflection unit 240, which is disposed on the reference frame 100 and is used to reflect the laser emitted by the laser emitting unit 210, so that the laser enters the optical path range extending unit 220 after passing through the sound inlet channel twice.

[0038] In this optimization scheme, each acoustic and optical sensor 200 is provided with a reflection unit 240, and the reflection unit 240 can be a reflector or can be composed of multiple spectroscopes, as long as the light beam reflection can be achieved. When the laser emitting unit 210 of the first acoustic and optical sensor 200 emits a laser, the light enters the sound inlet channel and is emitted to the second acoustic and optical sensor 200. Under the action of the reflection unit 240, it returns to the first acoustic and optical sensor 200, enters the optical path extension unit 220 of the first acoustic and optical sensor 200, and is finally received by the laser receiving unit. It can be seen that each group of acoustic and optical sensor 200 components can emit two horizontal or vertical laser beams. As long as two groups of acoustic and optical sensor 200 components can form a 2*2 laser array, this structure is more compact and simple than the existing scheme. The reflection unit 240 is set in this optimization scheme because the space is limited, and the light path changes direction after reflection, so that the light beam is incident on the inside of the optical path extension unit 220. The sensitivity can be improved by multiple reflections in the optical path extension unit 220.

[0039] In this optimization scheme, if Figure 5 As shown, the acoustic-optic sensor further includes a spectroscopic unit, the spectroscopic unit includes a first spectrometer 262 and a second spectrometer 263, the first spectrometer 262 and the second spectrometer 263 are both arranged on one side of the optical path range extender unit, so that the laser passes through the first spectrometer 262 and the second spectrometer 263 in sequence, passes through the sound inlet channel back and forth, and then passes through the second spectrometer 263 and the first spectrometer 262 in sequence to enter the optical path range extender unit. The spectroscopic unit further includes a reflector 261, the laser emitting unit and the spectroscopic unit are respectively arranged on two adjacent sides of the optical path range extender unit, and the reflector 261 is used to vertically reflect the laser emitted by the laser emitting unit into the first spectrometer 262 and the second spectrometer 263.

[0040] In this optimization scheme, Figure 5 This is the optical path diagram given by this optimization scheme, and its working process is as follows: the laser emitted by the laser emitting unit 210 is vertically reflected by the reflector 261, enters the first beam splitter 262, and is divided into two paths, one of which is horizontally emitted into the second beam splitter 263, and then divided into two paths, one of which is vertically reflected into the sound inlet channel; the reflection unit 240 reflects the laser back, so that the laser enters the second beam splitter 263 and the first beam splitter 262 in the opposite direction of the original, and is divided into two paths in the first beam splitter 262, one of which is reflected downward and enters the optical path extension unit 220. Figure 3As shown, the laser emitting unit 210, the optical path extending unit 220, the laser receiving unit 230 and the spectrometer unit 260 of the optimization scheme are all arranged on the same plane. This is because the optical path is optimized in the present scheme, and only two spectrometers are used to enable the laser to pass through the sound inlet channel twice, and then the optical path extending unit 220 is used to improve the sensitivity of optical sensing detection; in addition, the optical path design is compact, and the collimator 212, the reflector 261, the first spectrometer 262, the second spectrometer 263, the laser receiving unit 230 and the reflecting unit 240 can be as close to the corners of the optical path extending unit 220 as possible, which reduces the volume of the acoustic and optical sensor 200, and thus reduces the volume of the entire hydrophone.

[0041] In an optimization scheme, if Figure 1 As shown, the structure of the reference frame 100 is optimized. A plurality of mounting posts 110 are provided on the side of the reference frame 100, and the acoustic and optical sensors 200 are mounted on two adjacent mounting posts 110, so that the two acoustic and optical sensors 200 of each pair of the acoustic and optical sensing components are parallel to each other. The acoustic and optical sensor 200 also includes a mounting plate 250, which is mounted on two adjacent mounting posts 110. The laser emitting unit 210, the optical path extending unit 220, the laser receiving unit 230 and the spectroscopic unit 260 are all arranged on the mounting plate 250, and the direction in which the optical path extending unit 220 reflects the laser is parallel to the mounting plate 250. The laser emitting unit 210 and the laser receiving unit 230 are mounted on the mounting plate 250 at a position close to the support post of the reference frame 100.

[0042] In this optimization scheme, if Figure 1 As shown, the number of mounting posts 110 is an even number, and a corresponding number of acoustic and optical sensors 200 are set accordingly. In this solution, the acoustic and optical sensor 200 is designed as a plate as a whole, and the acoustic and optical sensor 200 is installed between two mounting posts 110, so that the laser emitting unit 210, the reflection unit 240, the optical path extension unit 220 and the laser receiving unit 230 are close to the reference frame 100, reducing the overall volume of the device. The number of layers that the acoustic and optical sensor components can be set depends on the height of the mounting posts 110. In the lightest case, the acoustic and optical sensor components are set with one layer, and each layer is set with 2 groups of acoustic and optical sensor components. At this time, the shape of the reference frame 100 is a rectangular parallelepiped.

[0043] In the second embodiment, if Figure 6 As shown, a miniaturized laser acoustic field structure is proposed, which includes the structure described in the first embodiment and also includes a shell 300, in which the reference frame 100 and several groups of the acoustic-optical sensor components are arranged.

[0044] In this embodiment, the housing 300 is a sealed hollow body, and all components including the reference frame 100 and the acoustic and optical sensing assembly are arranged inside to prevent the components from being infiltrated with water or being in a wet state. In addition, it can also play a role in isolating the acoustic and optical sensing area from the external environment. Although no glass window for the laser to enter and exit the acoustic channel is shown, it can be understood that the glass window is arranged on the inner side of the housing 300, and the actual number and position are determined according to actual needs.

[0045] In a third embodiment, if Figure 6 As shown, a hydrophone is proposed, which includes the structure described in the first embodiment or the second embodiment, and also includes a cable 400 and an electronic compartment, one end of the cable 400 is connected to the acoustic and optical sensor assembly, and the other end is connected to the electronic compartment.

[0046] In this embodiment, by setting the cable 400 and the electronic compartment, other electronic devices, such as a control unit, a power supply, etc., can be set in the electronic compartment, so as to avoid the electronic devices in the electronic compartment affecting the acoustic and optical sensing components, and at the same time, the space can be reasonably used to avoid crowding in the detection sensing area. The hydrophone of this embodiment has a compact structure and a small size, thanks to the design of the miniaturized laser acoustic field structure, which is mainly reflected in: a reasonable optical path design, which reduces the number of optical elements; most of the optical elements surround the optical path range extension unit 220, and two optical path range extension units 220 are arranged in parallel on the reference frame 100, which can make the entire structure more compact.

[0047] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A miniaturized laser acoustic field structure, characterized in that: The miniaturized laser acoustic field structure comprises: The reference frame has a sound inlet channel extending therethrough; A plurality of groups of acoustic-optical sensing components are arranged on the reference frame; each group of the acoustic-optical sensing components includes two acoustic-optical sensors, and the two acoustic-optical sensors are arranged relative to the sound inlet channel; the acoustic-optical sensor includes a laser emitting unit, an optical path range extending unit and a laser receiving unit, one end of the optical path range extending unit is connected to the laser emitting unit, and the other end is connected to the laser receiving unit, and the direction of the laser passing through the sound inlet channel is perpendicular to the direction of the laser reflected in the optical path range extending unit; The two optical path range-extending units of each group of the acoustic-optical sensing components are arranged laterally opposite to each other; The acoustic-optic sensor further includes a reflection unit, which is disposed on the reference frame and is used to reflect the laser emitted by the laser emitting unit so that the laser passes through the sound inlet channel twice and then enters the optical path range extending unit; The acoustic-optic sensor further includes a spectroscopic unit, the spectroscopic unit including a first spectrometer and a second spectrometer, the first spectrometer and the second spectrometer are both arranged on one side of the optical path range extender unit, so that the laser sequentially passes through the first spectrometer and the second spectrometer, passes through the sound inlet channel back and forth, and then sequentially passes through the second spectrometer and the first spectrometer to enter the optical path range extender unit; The spectroscopic unit further includes a reflector. The laser emitting unit and the spectroscopic unit are respectively arranged on two adjacent sides of the optical path extending unit. The reflector is used to vertically reflect the laser emitted by the laser emitting unit into the first spectroscope and the second spectroscope.

2. The miniaturized laser acoustic field structure according to claim 1, characterized in that: A plurality of mounting posts are arranged on the side of the reference frame, and the acoustic and optical sensors are mounted on two adjacent mounting posts, so that the two acoustic and optical sensors of each group of the acoustic and optical sensor components are parallel to each other.

3. The miniaturized laser acoustic field structure according to claim 2, characterized in that: The acoustic-optic sensor also includes a mounting plate, which is mounted on two adjacent mounting columns. The laser emitting unit, the optical path extending unit, the laser receiving unit and the spectroscopic unit are all arranged on the mounting plate, and the direction in which the optical path extending unit reflects the laser is parallel to the mounting plate.

4. The miniaturized laser acoustic field structure according to claim 3, characterized in that: The number of the mounting posts is 4, and the number of the acoustic and optical sensing components is a multiple of 2.

5. The miniaturized laser acoustic field structure according to claim 1, characterized in that: The miniaturized laser acoustic field structure also includes a shell, and the reference frame and several groups of the acoustic and optical sensing components are arranged in the shell.

6. The miniaturized laser acoustic field structure according to claim 1, characterized in that: The optical path extension unit comprises a module body and two plane reflectors, wherein the two plane reflectors are arranged in parallel on both sides of the module body, so that the laser beam incident into the module body is reflected back and forth between the two plane reflectors.

7. A hydrophone, characterized in that: The hydrophone comprises a cable, an electronic compartment and the miniaturized laser acoustic field structure according to any one of claims 1 to 6, wherein one end of the cable is connected to the acoustic-optical sensing assembly, and the other end is connected to the electronic compartment.

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