阅读说明：本技术 一种应用于光纤多普勒测速仪的大景深光学天线装置 (Large depth-of-field optical antenna device applied to optical fiber Doppler velocimeter ) 是由 杨钰城 郝歌扬 吴国俊 吕沛 吕小鹏 于 2019-10-12 设计创作，主要内容包括：本发明涉及一种应用于光纤多普勒测速仪的大景深光学天线装置,解决现有激光多普勒测量过程中存在空间光与光纤间耦合损耗较大、测量行程变小以及测量精度降低的问题。该装置包括镜头组件、光纤快速连接器组件、压圈、连接光纤和支座；镜头组件包括前镜筒、后镜筒、准直透镜、C透镜调节环和C透镜；前镜筒设置在支座上,准直透镜安装在前镜筒的一端,前镜筒的另一端与后镜筒连接,C透镜调节环安装在后镜筒内,C透镜安装在C透镜调节环内；光纤快速连接器组件包括插座及插头；插座包括母插座、第一楔形透镜和第一插针；插头包括公插头、锁紧螺母、第二插针、第二楔形透镜和光纤尾纤；插头和插座通过第二插针、第一插针连接。(The invention relates to a large depth-of-field optical antenna device applied to an optical fiber Doppler velocimeter, which solves the problems of large coupling loss between space light and optical fibers, small measuring stroke and low measuring precision in the existing laser Doppler measuring process. The device comprises a lens assembly, an optical fiber quick connector assembly, a pressing ring, a connecting optical fiber and a support; the lens component comprises a front lens barrel, a rear lens barrel, a collimating lens, a C lens adjusting ring and a C lens; the front lens cone is arranged on the support, the collimating lens is arranged at one end of the front lens cone, the other end of the front lens cone is connected with the rear lens cone, the C lens adjusting ring is arranged in the rear lens cone, and the C lens is arranged in the C lens adjusting ring; the optical fiber quick connector assembly comprises a socket and a plug; the socket comprises a female socket, a first wedge-shaped lens and a first contact pin; the plug comprises a male plug, a locking nut, a second contact pin, a second wedge-shaped lens and an optical fiber pigtail; the plug and the socket are connected through the second contact pin and the first contact pin.)

1. The utility model provides a be applied to optical fiber Doppler velocimeter's big depth of field optical antenna device which characterized in that: comprises a lens component (1), an optical fiber quick connector component (2), a pressing ring (3), a connecting optical fiber (4) and a support (5);

the lens assembly (1) comprises a front lens barrel (101), a rear lens barrel (102), a collimating lens (103), a C lens adjusting ring (105) and a C lens (106); the front lens barrel (101) is arranged on the support (5), the collimating lens (103) is installed at one end of the front lens barrel (101), the other end of the front lens barrel (101) is connected with the rear lens barrel (102), the C lens adjusting ring (105) is installed in the rear lens barrel (102), and the C lens (106) is installed in the C lens adjusting ring (105);

the optical fiber quick connector assembly (2) comprises a socket (201) and a plug (202);

the socket (201) comprises a female socket (2011), a first wedge lens (2012) and a first pin (2013); the female socket (2011) is mounted at the tail end of the rear lens barrel (102) through a pressing ring (3), the first wedge-shaped lens (2012) is mounted in an axial through hole of the female socket (2011), and the first wedge-shaped lens (2012) is connected with the C lens (106) through a connecting optical fiber (4);

the plug (202) comprises a male plug (2021), a locking nut (2022), a second pin (2024), a second wedge-shaped lens (2025) and a fiber pigtail (2026); the second wedge-shaped lens (2025) is arranged in the axial through hole of the male plug (2021), and the wedge surface of the second wedge-shaped lens is parallel to and adjacent to the wedge surface of the first wedge-shaped lens (2012); one end of the first pin (2013) is inserted into the female socket (2011), the other end of the first pin is inserted into the male plug (2021), one end of the second pin (2024) is inserted into the male socket (201), and the other end of the second pin is inserted into the female plug (202); the locking nut (2022) is sleeved on the male plug (2021) and the female plug (202) and is used for connecting the male plug (2021) and the female plug (202); the optical fiber pigtail (2026) is arranged in the axial through hole of the male plug (2021) and is connected with the second wedge-shaped lens (2025).

2. The large depth-of-field optical antenna device applied to the optical fiber Doppler velocimeter according to claim 1, wherein: the tail end of the male plug (2021) is provided with a stop nut (2023) to prevent the locking nut (2022) from slipping off the male plug (2021), and the collimating lens (103) is arranged at one end of the front lens barrel (101) through a lens pressing ring (104).

3. The large depth-of-field optical antenna device applied to the optical fiber doppler velocimeter according to claim 2, wherein: the first wedge lens (2012) is a first 8 ° wedge lens and the second wedge lens (2025) is a second 8 ° wedge lens.

4. The large depth-of-field optical antenna device applied to the optical fiber Doppler velocimeter according to claim 1, 2 or 3, wherein: the distance between the C lens (106) and the collimating lens (103) is 252.8 mm.

5. The large depth-of-field optical antenna device applied to the optical fiber Doppler velocimeter according to claim 4, wherein: the front lens barrel (101) is provided with a flange, and the front lens barrel (101) is arranged on the support (5) through the flange.

6. The large depth-of-field optical antenna device applied to the optical fiber Doppler velocimeter according to claim 5, wherein: three glue injection holes are uniformly distributed in the rear lens barrel (102) and the C lens adjusting ring (105) along the circumference, the C lens (106) and the C lens adjusting ring (105) are bonded and fixed on the rear lens barrel (102) through epoxy resin glue, three threaded holes are formed in the male plug (2021) and the female plug (202) along the circumference, the first wedge-shaped lens ring is bonded and fixed on the female plug (202) through the epoxy resin glue, and the second wedge-shaped lens ring is bonded and fixed on the male plug (2021) through the epoxy resin glue.

7. The large depth-of-field optical antenna device applied to the optical fiber Doppler velocimeter according to claim 6, wherein: the two ends of the first contact pin (2013) and the second contact pin (2024) are arranged to be guiding conical surfaces, so that the first contact pin (2013) and the second contact pin (2024) can be conveniently inserted into blind holes of the male plug (2021) and the female plug (202), and the first contact pin (2013) and the second contact pin (2024) are in interference fit with the blind holes of the male plug (2021) and the female plug (202) respectively.

8. The large depth-of-field optical antenna device applied to the optical fiber Doppler velocimeter according to claim 7, wherein: the female socket (2011) is provided with two bosses distributed along the circumference, and the bosses slide in along a groove at the tail end of the rear lens barrel (102) and are used for positioning and limiting the female socket (2011) and the rear lens barrel (102).

9. The large depth-of-field optical antenna device applied to the optical fiber doppler velocimeter according to claim 8, wherein: the aperture of the C lens (106) is 3.5mm, the spherical radius R4 is 2.8mm, the length is 3.4mm, and the material is N-SF 11.

10. The large depth-of-field optical antenna device applied to the optical fiber doppler velocimeter according to claim 9, wherein: the collimating lens (103) is a double-cemented achromat, the caliber is 40mm, the focal length is 250mm, the radius is respectively R1-153.435 mm, R2-111.75 mm, R3-329.39, the center thickness is 8.6mm, the edge thickness is 6.7mm, the material of a double-convex lens in the double-cemented achromat is H-K9, and the material of a double-concave lens is H-ZF 2.

Technical Field

The invention relates to the field of laser Doppler velocity and acceleration measurement, in particular to a large-depth-of-field optical antenna device applied to an optical fiber Doppler velocimeter.

Background

At present, the following methods are mainly used for measuring the speed and the acceleration of a continuously moving object: numerical simulation, microwave interferometry, laser doppler, and the like. The numerical simulation method obtains corresponding parameters through theoretical derivation based on a series of assumed conditions, and the result is inaccurate and has a large difference with the actual result. The microwave interference measurement technology is limited by factors such as wavelength, relatively low in precision of testing objects with low moving speed and short stroke, and meanwhile is easily influenced by electromagnetic interference. The laser Doppler technology has the characteristics of high spatial resolution, no influence by the state of a moving object, strong anti-electromagnetic interference capability, high measurement accuracy and the like, and is widely applied to the fields of military, aviation and the like.

Aiming at the case of applying laser Doppler velocity measurement, the laser is generally emitted by a laser, is emitted to the space through an optical fiber and a lens, and then reaches the surface of a measured object after being collimated, and the space light enters the optical fiber again after being diffused, and finally the signal is received by a collecting card after the subsequent series of processing. In the transmitting and receiving processes, the problem of large coupling loss exists between space light and optical fibers, and meanwhile, the optical fiber joint adopted at the optical fiber connection plugging part has the conditions of large loss and unstable plugging loss at each time, so that the measurement stroke is reduced, the measurement precision is reduced, and the final result analysis is influenced.

Disclosure of Invention

The invention aims to solve the problems of large coupling loss between space light and optical fibers, small measuring stroke and low measuring precision in the existing laser Doppler measuring process, and provides a large-depth-of-field optical antenna device applied to an optical fiber Doppler velocimeter, which can realize the speed and acceleration measurement of low loss, large stroke, long distance and high precision by laser Doppler, and is simple to operate and easy to implement during the test.

In order to achieve the purpose, the invention adopts the following technical scheme:

a large depth of field optical antenna device applied to an optical fiber Doppler velocimeter comprises a lens component, an optical fiber quick connector component, a pressing ring, a connecting optical fiber and a support; the lens component comprises a front lens barrel, a rear lens barrel, a collimating lens, a C lens adjusting ring and a C lens; the front lens cone is arranged on the support, the collimating lens is arranged at one end of the front lens cone, the other end of the front lens cone is connected with the rear lens cone, the C lens adjusting ring is arranged in the rear lens cone, and the C lens is arranged in the C lens adjusting ring; the optical fiber quick connector assembly comprises a socket and a plug; the socket comprises a female socket, a first wedge-shaped lens and a first contact pin; the female socket is arranged at the tail end of the rear lens barrel through a pressing ring, the first wedge-shaped lens is arranged in an axial through hole of the female socket, and the first wedge-shaped lens is connected with the C lens through a connecting optical fiber; the plug comprises a male plug, a locking nut, a second contact pin, a second wedge-shaped lens and an optical fiber pigtail; the second wedge-shaped lens is arranged in the axial through hole of the male plug, and the wedge surface of the second wedge-shaped lens is parallel to and adjacent to the wedge surface of the first wedge-shaped lens; one end of the first contact pin is inserted into the female socket, the other end of the first contact pin is inserted into the male plug, one end of the second contact pin is inserted into the male socket, and the other end of the second contact pin is inserted into the female plug; the locking nut is sleeved on the male plug and the female plug and is used for connecting the male plug and the female plug; the optical fiber pigtail is arranged in the axial through hole of the male plug and is connected with the second wedge-shaped lens.

Further, the tail end of the male plug is provided with a blocking nut to prevent the locking nut from slipping off the male plug, and the collimating lens is mounted at one end of the front lens barrel through a lens pressing ring.

Further, the first wedge lens is a first 8 ° wedge lens, and the second wedge lens is a second 8 ° wedge lens.

Further, the distance between the C lens and the collimating lens is 252.8 mm.

Furthermore, a flange is arranged on the front lens barrel, and the front lens barrel is mounted on the support through the flange.

Furthermore, three glue injection holes are uniformly distributed in the rear lens cone and the C lens adjusting ring along the circumference, the C lens and the C lens adjusting ring are bonded and fixed on the rear lens cone through epoxy resin glue, three threaded holes are formed in the male plug and the female plug along the circumference, the first wedge-shaped lens ring is bonded and fixed on the female plug through epoxy resin glue, and the second wedge-shaped lens ring is bonded and fixed on the male plug through epoxy resin glue.

Further, first contact pin and second contact pin both ends set up to direction conical surface, are convenient for insert in the blind hole of public plug and female plug, first contact pin and second contact pin are interference fit with the blind hole of public plug and female plug.

Furthermore, the female socket is provided with two bosses distributed along the circumference, and the bosses slide in along the groove at the tail end of the rear lens cone and are used for positioning and limiting the female socket and the rear lens cone.

Furthermore, the aperture of the C lens is 3.5mm, the spherical radius R4 is 2.8mm, the length is 3.4mm, and the material is N-SF 11.

Further, the collimating lens is a double-cemented achromat lens, the caliber is 40mm, the focal length is 250mm, the radius is R1-153.435 mm, R2-111.75 mm, R3-329.39, the center thickness is 8.6mm, the edge thickness is 6.7mm, the material of the double-convex lens in the double-cemented achromat lens is H-K9, and the material of the double-concave lens is H-ZF 2.

Compared with the prior art, the invention has the following advantages:

the invention provides an all-fiber laser Doppler velocity measurement optical transceiving antenna device, which can realize stable and reliable light path transceiving transmission, has lower space light and optical fiber coupling loss, can realize transmission measurement at a large distance, can ensure that an optical fiber is small and stable in each plugging loss value by an optical fiber quick connecting component in the device, and is simple and convenient to install, adjust, use and operate and easy to realize.

Drawings

Fig. 1 is a cross-sectional view of a large depth-of-field optical antenna device for use in an optical fiber doppler velocimeter according to the present invention;

FIG. 2 is a schematic diagram of a large depth-of-field optical antenna device for an optical fiber Doppler velocimeter according to the present invention;

FIG. 3 is a cross-sectional view of the lens assembly of the present invention;

FIG. 4a is a cross-sectional view of a fiber optic quick connector assembly of the present invention;

FIG. 4b is an outline view of the fiber optic quick connector assembly of the present invention;

FIG. 5 is a cross-sectional view of a socket according to the present invention;

FIG. 6 is a cross-sectional view of a plug of the present invention;

FIG. 7 is a cross-sectional view of the rear barrel of the present invention;

FIG. 8a is a front view of a male plug of the present invention;

fig. 8B is a cross-sectional view B-B of fig. 8 a.

Reference numerals: 1-lens component, 2-optical fiber quick connector component, 3-clamping ring, 4-connecting optical fiber, 5-support, 6-screw, 101-front lens cone, 102-rear lens cone, 103-collimating lens, 104-lens clamping ring, 105-C lens adjusting ring, 106-C lens, 201-socket, 202-plug, 2011-female socket, 2012-first wedge lens, 2013-first pin, 2021-male plug, 2022-locking nut, 2023-stop nut, 2024-second pin, 2025-second wedge lens, 2026-optical fiber pigtail.

Detailed description of the preferred embodiments

The invention is described in further detail below with reference to the figures and specific embodiments.

The invention provides a large depth of field optical antenna device applied to an optical fiber Doppler velocimeter, wherein the depth of field of measurement is more than 25 meters, and the continuous and accurate measurement of the speed and the acceleration of a measured target can be realized. The optical antenna device can realize stable and reliable laser emission and reception, so that echo signals within the range of 25 m of depth of field have higher signal-to-noise ratio, and have lower spatial light and optical fiber coupling loss, and long-distance transmission measurement can be realized. The optical fiber quick connection assembly in the device not only enables the optical fiber to be small and stable in plugging loss value each time, but also reduces the risk of burning out of the optical fiber joint under the condition of high-power laser output, improves the reliability of the system, and enables the whole system to be simple and convenient to install, adjust, use and operate and easy to realize.

As shown in fig. 1 and fig. 2, the all-fiber laser doppler velocity measurement optical transceiver antenna device provided by the present invention includes a lens assembly 1, an optical fiber quick connector assembly 2, a pressing ring 3, a connecting optical fiber 4, a support 5 and a screw 6. Wherein connect optic fibre 4 and be connected C lens 106 in the lens subassembly 1 with optic fibre quick connector subassembly 2, guarantee the normal transmission of light path, after putting into the lens cone with optic fibre quick connector, use clamping ring 3 to compress tightly fixedly.

As shown in fig. 3 and 7, the lens assembly 1 includes a front lens barrel 101, a rear lens barrel 102, a collimator lens 103, a lens pressing ring 104, a C lens adjusting ring 105, a C lens 106, and the like. The lens clamping ring 104 may fix the collimating lens 103 on the front end boss of the front barrel 101. The front lens cone 101 is provided with a flange which can be connected and fixed with the support 5, the rear end of the front lens cone 101 is connected with the rear lens cone 102, the C lens adjusting ring 105 is arranged in the rear lens cone 102, and the C lens 106 is arranged in the C lens adjusting ring 105; three glue injection holes are uniformly distributed on the rear lens barrel 102 and the C lens adjusting ring 105 along the circumference, and the positions of the C lens 106 and the C lens adjusting ring 105 are adjusted by utilizing a five-axis adjusting lens frame, so that laser emitted from the C lens 106 is emitted along the axial direction of the lens barrel, and meanwhile, the distance between the C lens 106 and the collimating lens 103 is ensured to be 252.8 mm. After the adjustment is finished, the positions of the C lens 106 and the C lens adjusting ring 105 are bonded and fixed by using epoxy resin glue, and the C lens is aired in the air for 24 hours to ensure the bonding strength. The lens assembly 1 functions to launch and collimate laser light within the optical fiber while coupling received spatial light into the optical fiber. The C lens 106 is used for transmitting and receiving the end laser, and the collimating lens 103 is used for collimating the transmitted laser and converging the received echo signal.

As shown in fig. 4a and 4b, the fiber optic quick connector assembly 2 includes a receptacle 201 and a plug 202; when the test is used, the contact pin of the plug 202 can be directly inserted into the corresponding hole of the socket 201, so that the stability of optical path transmission is ensured.

As shown in fig. 5, the socket 201 includes a female socket 2011, a first wedge lens 2012 and a first pin 2013, and the first wedge lens 2012 can be a first 8 wedge lens or other angled wedge lens. The female socket 2011 is mounted at the end of the rear barrel 102 through the pressing ring 3, the first 8 ° wedge lens is mounted in the axial through hole of the female socket 2011, and the first 8 ° wedge lens is connected with the C lens 106 through the connecting optical fiber 4. Female socket 2011 is along three screw holes of circumference distribution, and it is fixed to use epoxy glue to bond first 8 wedge lenses. The two ends of the first contact pin 2013 are guiding conical surfaces, so that the first contact pin can be conveniently inserted into a blind hole of the female socket 2011. Meanwhile, interference fit between the first contact pin 2013 and the blind hole of the female socket 2011 is achieved, and looseness and sliding off during plugging and unplugging are prevented. The female socket 2011 is provided with two bosses distributed along the circumference, and the bosses can slide in along the groove at the tail end of the rear lens barrel 102 to play a role in positioning and limiting.

As shown in fig. 6, 8a, and 8b, the plug 202 includes a male plug 2021, a locking nut 2022, a stop nut 2023, a second pin 2024, a second wedge lens 2025, and a fiber pigtail 2026, and the second wedge lens 2025 may be a second 8 ° wedge lens or other wedge lens. The second 8 ° wedge lens is disposed on the axial through hole of the male plug 2021, and a wedge surface thereof is parallel to and adjacent to a wedge surface of the first 8 ° wedge lens; one end of the first pin 2013 is inserted into the female socket 2011, the other end of the first pin is inserted into the male plug 2021, one end of the second pin 2024 is inserted into the male socket 201, and the other end of the second pin is inserted into the female plug 202; the locking nut 2022 is sleeved on the male plug 2021 and the female plug 202 and is used for connecting the male plug 2021 and the female plug 202; the fiber pigtail 2026 is disposed within the axial through-hole of the male plug 2021 and is connected to a second 8 ° wedge lens. Two ends of the second pin 2024 are guiding tapered surfaces, so as to be conveniently inserted into the blind hole of the male plug 2021. Meanwhile, the second pin 2024 and the blind hole of the male plug 2021 should be in interference fit, so as to prevent loosening and slipping during plugging. The end of the male plug 2021 is provided with a stop nut 2023, and the stop nut 2023 is used to prevent the lock nut 2022 from slipping off the male plug 2021 and being lost. During installation, the locking nut 2022 is sleeved on the optical axis of the male plug 2021, and the stop nut 2023 is screwed on the end thread of the male plug 2021. Three glue injection holes are also formed in the male plug 2021 along the circumference, the position of the second 8-degree wedge-shaped lens is adjusted through the multi-dimensional adjusting mirror frame, so that the loss of light entering the first 8-degree wedge-shaped lens in the female socket 2011 is minimized, and the position is determined and then the position is fixed by epoxy resin glue in a sealing mode. Because the socket 201 and the plug 202 respectively have 1 pin, blind plugging and unplugging can be realized, and misplugging is prevented. During testing, after the plug 202 is inserted into the socket 201, the plug can be locked and fixed by the locking nut 2022, so that the plug is prevented from being accidentally removed.

The optical fiber quick connector has the advantages that the first 8-degree wedge lens and the second 8-degree wedge lens are used for reducing mirror reflection in optical path transmission so as to reduce optical transmission loss, the optical fiber quick connector is used for quickly connecting and locking the optical antenna and the measurement and control system during testing, and the design of the structure can ensure that plugging loss is stable at every time and has a low plugging loss value.

The aperture of the C lens 106 of the invention is 3.5mm, the spherical radius R4 is 2.8mm, the length is 3.4mm, and the material is N-SF 11. The collimating lens 103 is a double-cemented achromat, the caliber is 40mm, the focal length is 250mm, the radius is respectively R1-153.435 mm, R2-111.75 mm, R3-329.39, the center thickness is 8.6mm, the edge thickness is 6.7mm, the material of a biconvex lens in the double-cemented achromat is H-K9, and the material of a biconcave lens is H-ZF 2.

The distance between the C lens 106 and the double-cemented achromat is 252.8mm, the distance 252.8mm is an optimal parameter, the calculation method adopts a transmission model that Gaussian beams pass through a thin lens, the double-cemented achromat is equivalent to the thin lens, and the specific calculation process is as follows:

1) firstly, writing out a transmission matrix M of the C lens 106 and the double-cemented achromatic lens according to the structural parameters of the C lens and the double-cemented achromatic lens₁And M₂Where the C lens 106 is equivalent in terms of a thick lens:

2) when the laser beam is emitted from the optical fiber, the laser beam waist is positioned at the end face of the optical fiber, namely the beam waist position of an object space, the beam waist radius at the position is the equivalent mode field radius of the optical fiber at 1550nm, and w is taken₀10um, i.e. the laser q parameter at this timeIs composed of

As can be seen from the structure of the C lens 106, if the distance between the optical fiber and the rear end face of the C lens 106 is 0.2mm, the ABCD matrix of the laser light when passing through the C lens 106 can be expressed as:

therefore, after passing through the C lens 106, the q parameter q of the laser light_fCan be expressed as:

beam waist position l of laser at this time₁Comprises the following steps:

where re represents taking the real part and im represents taking the imaginary part.

3) The laser q parameter q _ lens after being collimated by the double-cemented achromat satisfies the following relation

Wherein, it is made

w₂Denotes a waist radius, l, of the laser beam collimated by the collimator lens 103₂The collimated beam waist position is indicated, i.e. l' 25000mm, in order to achieve a detection depth of field of 25 m.

If the distance between the waist of the laser beam before collimation and the cemented doublet is assumed to be b, the ABCD matrix of the beam when transmitted from the C lens 106 to the collimating lens 103 can be expressed as:

then q _ lens can be represented again as:

b is 251.24, which can be obtained by combining (6) and (8), i.e. the distance between the C lens 106 and the collimator lens 103 is l₁+b＝252.8mm。