CN211603608U - Femtosecond laser direct-writing fiber grating preparation device based on machine learning image recognition - Google Patents
Femtosecond laser direct-writing fiber grating preparation device based on machine learning image recognition Download PDFInfo
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- CN211603608U CN211603608U CN202020205854.4U CN202020205854U CN211603608U CN 211603608 U CN211603608 U CN 211603608U CN 202020205854 U CN202020205854 U CN 202020205854U CN 211603608 U CN211603608 U CN 211603608U
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Abstract
The utility model discloses a femto second laser directly writes fiber grating preparation facilities based on machine learning image recognition, directly write optical path system including femto second laser, the real-time imaging system of visible light, orientation module and image recognition program control module, femto second laser directly writes optical path system, the real-time imaging system of visible light and orientation module all with image recognition program control module electric connection, according to waiting to carve the picture of carving of optic fibre, image recognition program control module treats through orientation module that carves optic fibre and fixes a position, and directly write optical path system through femto second laser and carve the optic fibre of carving after fixing a position, observe the imaging picture of carving the optic fibre of waiting to carve after carving through the real-time imaging system of visible light simultaneously. The utility model discloses can fix a position optic fibre Bragg grating orbit, realize by the micron order of magnitude to the fiber grating of the arbitrary length in the meter level scope, also can realize the Bragg fiber grating of arbitrary type.
Description
Technical Field
The utility model relates to a femto second laser is directly write and is prepared optic fibre bragg grating technical field, especially relates to a femto second laser is directly write optic fibre grating preparation facilities based on machine learning image recognition.
Background
The fiber grating has the characteristics of small volume, good wavelength selectivity, easy coupling and integration with fiber devices and systems, convenient use and maintenance and the like, and is a very important fiber device in the fields of fiber communication, fiber lasers, fiber sensing and the like. The preparation method of the fiber grating mainly comprises a double-beam interference method based on ultraviolet band laser and a phase mask plate preparation method, and a direct writing method based on near-infrared femtosecond laser and a phase mask plate preparation method. The former needs the fiber core of the optical fiber to have certain photosensitivity, and the latter overcomes the limitation of the former on the optical fiber and can prepare the fiber grating in any type of quartz glass optical fiber. In addition, the length and the type of the fiber grating obtained by the phase mask preparation method depend on the length and the type of the used phase mask, and the preparation cost is high. However, the direct writing preparation method based on the near infrared femtosecond laser avoids the limitation of a phase mask plate, and can flexibly prepare optical fiber gratings with different lengths and any types by accurately controlling the moving speed of an optical fiber or a femtosecond laser focused beam and the repetition frequency of the femtosecond laser, and the cost is low. Therefore, in recent years, the near-infrared femtosecond laser direct writing fiber grating preparation technology is receiving more attention and favor from the industry and academia at home and abroad.
The femtosecond laser direct writing method for preparing the fiber grating focuses the incident femtosecond laser beam into the fiber core of the fiber, and carries out point-by-point exposure along the axial direction of the fiber, so that the refractive index of the fiber core forms a periodically distributed grating structure along the axial direction. By utilizing a visible light imaging technology and a high-precision XYZ three-dimensional displacement platform control technology, a focused light beam can be accurately focused to the center of a fiber core, and meanwhile, a grating structure following a certain track is formed in the fiber core by moving a laser beam or an optical fiber with high precision. When the grating track coincides with the central axis of the optical fiber, the coupling efficiency of the grating is highest and the backlight loss is lowest. When the grating track deviates from the central axis of the optical fiber, the problems of low coupling efficiency of the grating, unnecessary cladding mode generation, grating insertion loss and the like can be caused. Therefore, the precise collimation of the grating track is an important prerequisite for preparing the high-quality fiber grating by the femtosecond laser direct writing method.
SUMMERY OF THE UTILITY MODEL
Utility model purpose: in preparing fiber grating technique to femto second laser direct writing method, the current actual orbit based on two points are fixed the method and obtain optic fibre is non-linear to lead to grating coupling efficiency low, repeatability poor, can't prepare the fiber grating's of certain length problem even, the utility model provides a femto second laser direct writing fiber grating preparation facilities based on machine learning image recognition.
The technical scheme is as follows: for realizing the purpose of the utility model, the utility model adopts the technical proposal that:
the femtosecond laser direct writing fiber grating preparation device comprises a femtosecond laser direct writing light path system, a visible light real-time imaging system, a positioning module and an image recognition program control module, wherein the femtosecond laser direct writing light path system, the visible light real-time imaging system and the positioning module are electrically connected with the image recognition program control module, the image recognition program control module positions an optical fiber to be engraved through the positioning module according to a picture to be engraved of the optical fiber to be engraved, the positioned optical fiber to be engraved is engraved through the femtosecond laser direct writing light path system, and the visible light real-time imaging system observes an imaged picture of the engraved optical fiber to be engraved.
Further, the optical fiber to be etched comprises a fiber core, a cladding and a coating layer, wherein the fiber core is arranged in the center of the optical fiber to be etched, the cladding is arranged outside the fiber core, the coating layer is arranged outside the cladding, and the material refractive index ranges of the fiber core and the cladding are as follows: 1.44-2.5.
The femtosecond laser direct writing optical path system comprises a near infrared femtosecond laser or amplifier, an electronic shutter, a combined lens, a dichroic mirror and a focusing lens, wherein the near infrared femtosecond laser or amplifier emits femtosecond laser beams, the femtosecond laser beams are transmitted into the dichroic mirror through the electronic shutter and the combined lens for high reflection, and the femtosecond laser beams after high reflection are focused in an optical fiber to be etched through the focusing lens to etch the optical fiber to be etched.
Furthermore, the combined lens comprises a half-wave plate I, a Glan laser wave plate and a half glass plate II, wherein the Glan laser wave plate is arranged in the middle of the half-wave plate I and the half glass plate II, and the focal centers of the half-wave plate I, the Glan laser wave plate and the half glass plate II are positioned on the same horizontal plane.
Further, the visible light real-time imaging system comprises a visible light source and a CCD camera, the visible light source emits a visible light beam, the visible light beam passes through the optical fiber to be etched and enters a focusing lens, the visible light beam is focused in a dichroic mirror through the focusing lens, the visible light beam simultaneously enters the CCD camera through the high transmittance of the dichroic mirror, and an imaging picture of the optical fiber to be etched is obtained in the CCD camera.
Furthermore, the positioning module comprises a three-dimensional displacement platform, a U-shaped groove assembly part is fixed on the three-dimensional displacement platform through a clamp of a three-dimensional adjusting frame, and the optical fiber to be etched is arranged inside the U-shaped groove assembly part through an optical fiber clamp.
Further, the U-shaped groove assembly part comprises a U-shaped groove, a cover glass and refractive index matching liquid, the optical fiber to be etched is placed in the middle of the U-shaped groove, the refractive index matching liquid is arranged between the optical fiber to be etched and the inner side of the U-shaped groove, and the cover glass is arranged on the upper surface of the U-shaped groove.
Further, the image recognition program control module comprises a computer and a data line, and the computer is electrically connected with the electronic shutter, the CCD camera and the three-dimensional displacement platform through the data line.
The utility model discloses a theory of operation:
s1: the femtosecond laser incident light path and the visible light imaging light path are coaxially confocal through the femtosecond laser direct writing light path system and the visible light real-time imaging system;
s2: opening the electronic shutter, enabling the near-infrared femtosecond laser or the amplifier to emit femtosecond laser beams, simultaneously opening imaging software in a CCD (charge coupled device) camera through the computer, enabling the CCD camera to start a real-time capture mode, adjusting the power of the near-infrared femtosecond laser or the amplifier until a bright light spot is seen in the imaging software, and marking the position of the bright light spot on a display screen of the computer;
s3: closing the electronic shutter (3), adjusting the position of the three-dimensional displacement platform (16), so that when the visible light source (9) emits a visible light beam (10), an imaging picture is obtained in the CCD camera (11), whether the marked bright light spot position is located at the center of a fiber core (12.1) of the imaging picture is confirmed, if the marked bright light spot position is located, the marked bright light spot position is kept unchanged, and if the marked bright light spot position is not located, the three-dimensional displacement platform (16) is moved until the marked bright light spot position is located at the center of the fiber core (12.1) of the imaging picture;
s4: searching the central axis track of the optical fiber in the area of the optical fiber grating to be etched;
s5: returning the X axis, the Y axis and the Z axis of the three-dimensional displacement platform to the starting position of the fiber bragg grating to be etched, simultaneously setting the X axis moving speed of the three-dimensional displacement platform, and setting the Y axis displacement and the Z axis displacement of the three-dimensional displacement platform according to the central axis track of the optical fiber;
s6: and setting the output power of the near-infrared femtosecond laser or the amplifier, opening the electronic shutter, starting an engraving program until the X axis of the three-dimensional displacement platform reaches the end position of the fiber bragg grating to be engraved, closing the electronic shutter, and finishing the preparation of the fiber bragg grating to be engraved.
Further, in step S1, the femtosecond laser incident light path and the visible light imaging light path are coaxially confocal, specifically as follows:
s1.1: enabling the femtosecond laser beam to vertically pass through the centers of the electronic shutter and the combined lens, and simultaneously enabling the femtosecond laser beam to enter the center of the dichroic mirror at 45 degrees, vertically entering the three-dimensional displacement platform after the femtosecond laser beam is subjected to high reflection by the dichroic mirror, and vertically entering the focusing lens;
s1.2: and after passing through a focusing lens and a dichroic mirror, the visible light beam vertically enters the center of an imaging chip of the CCD camera.
Has the advantages that: compared with the prior art, the technical scheme of the utility model following beneficial technological effect has:
(1) the utility model discloses can accurate location fiber bragg grating orbit to customize according to displacement platform's moving range and actual need, can realize by the micron level to the fiber bragg grating of the arbitrary length in the meter level scope, also can realize even fiber bragg grating, chirp fiber bragg grating, apodization fiber bragg grating, phase shift fiber bragg grating and sample fiber bragg grating through the repetition frequency, the rate of movement of program control femtosecond pulse and the position distribution in optic fibre, can be in order to realize the fiber bragg grating of arbitrary type;
(2) the utility model discloses an optical fiber size, material and type are all unrestricted, need not to carry out the preliminary treatment, and the optical fiber coating is unrestricted yet simultaneously, can take the coating to carve and write to strengthened the robustness of optic fibre Bragg grating, also improved the efficiency and the repeatability of optic fibre preparation, reduced the input cost.
Drawings
FIG. 1 is a drawing of a femtosecond laser direct writing fiber grating preparation device based on machine learning image recognition;
FIG. 2 is a schematic diagram of the structure of a fiber grating to be etched in a three-dimensional displacement platform according to the present invention;
FIG. 3 is a schematic cross-sectional view of an optical fiber to be etched according to the present invention, which is placed in a U-shaped groove;
fig. 4 is a microscope photograph of the present invention after the grating is written on the axial line in G652D and UHNA3 optical fibers;
fig. 5 is a transmission spectrum of a 50 mm long G652D fiber bragg grating of the present invention;
fig. 6 is a transmission spectrum diagram of a UHNA3 fiber bragg grating of 50 mm length according to the present invention;
the numbers in the figures correspond to part names:
1. a near infrared femtosecond laser or amplifier; 2. a femtosecond laser beam; 3. an electronic shutter; 4. a half-wave plate; 5. a Glan laser wave plate; 6. half slide; 7. a dichroic mirror; 8. a focusing lens; 9. a visible light source; 10. a beam of visible light; 11. a CCD camera; 12. an optical fiber to be etched; 12.1, a fiber core; 12.2, cladding; 12.3, coating layer; 13. an optical fiber clamp; 14. a U-shaped groove assembly; 14.1, a U-shaped groove; 14.2, cover glass; 14.3, refractive index matching fluid; 15. a clamp of the three-dimensional adjusting frame; 16. a three-dimensional displacement platform; 17. a computer; 18. a data line; 19. and (5) waiting to etch the fiber grating.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the drawings in the embodiments of the present invention are combined below to clearly and completely describe the technical solutions in the embodiments of the present invention. The described embodiments are some, but not all embodiments of the invention. Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention.
Example 1
Referring to fig. 1, the present embodiment provides a femtosecond laser direct-writing fiber grating preparation apparatus based on machine learning image recognition, and the femtosecond laser direct-writing fiber grating preparation apparatus is composed of a femtosecond laser direct-writing optical path system, a visible light real-time imaging system, a positioning module, and an image recognition program control module. The femtosecond laser direct writing optical path system, the visible light real-time imaging system and the positioning module are electrically connected with the image recognition program control module, the image recognition program control module positions the optical fiber 12 to be etched through the positioning module according to the picture to be etched of the optical fiber 12 to be etched, the positioned optical fiber 12 to be etched is etched through the femtosecond laser direct writing optical path system, and the imaged picture of the etched optical fiber 12 to be etched is observed through the visible light real-time imaging system.
Referring to fig. 2, the optical fiber 12 to be etched includes a core 12.1, a cladding 12.2 and a coating 12.3, and in this embodiment, the optical fiber 12 to be etched refers to a solid optical fiber with a central symmetrical cross section. The core 12.1 is arranged in the center of the optical fiber 12 to be etched, the core 12.1 is surrounded by the cladding 12.2, the cladding 12.2 is surrounded by the coating 12.3, namely, the diameter of the coating 12.3 is larger than that of the cladding 12.2, and the diameter of the cladding 12.2 is larger than that of the core 12.1. Specifically, the number of layers of the core 12.1 is 1, the number of layers of the cladding 12.2 is 1 or 2, and the number of layers of the coating layer 12.3 is 0 to 3, wherein when the number of layers of the coating layer 12.3 is 0, it means that the optical fiber 12 to be inscribed does not contain the coating layer 12.3.
Meanwhile, the refractive index ranges of the materials of the core 12.1 and the cladding 12.2 are: 1.44-2.5, are optical fibers prepared on the basis of quartz glass, fluoride glass, silicate glass, phosphate glass, borosilicate glass, sulfide glass, tellurite glass, and mixtures of these glass matrices. The core 12.1 diameter range is: 0.5-100 microns, cladding 12.2 diameter range: 50 μm to 2 mm.
In the femtosecond laser direct writing optical path system, the femtosecond laser direct writing optical path system comprises a near infrared femtosecond laser or amplifier 1, an electronic shutter 3, a combined lens, a dichroic mirror 7 and a focusing lens 8, wherein the combined lens comprises a half-wave plate I4, a Glan laser wave plate 5 and a half-glass plate II 6. Specifically, the near-infrared femtosecond laser or amplifier 1 is a femtosecond laser light source that emits a femtosecond laser beam 2, and the center wavelength range of the femtosecond laser light source is: 780 nm-1080 nm, pulse width range: 25 femtoseconds to 220 femtoseconds, and the repetition frequency range is as follows: 1 Hz-100 MHz. The electronic shutter 3 is used for controlling the on and off of femtosecond laser pulses during grating writing, the combined lens is used for adjusting the power and the polarization state of the femtosecond laser, the dichroic mirror 7 is used for realizing high reflection of incident femtosecond laser and high transmission of incident visible light, and the focusing lens 8 is used for focusing a converging light spot to a micrometer-scale micro lens or oil lens which is 10X, 20X,30X,40X,50X,60X,70X,80X,90X or 100X.
The femtosecond laser beam 2 sequentially passes through the electronic shutter 3, the half-wave plate I4, the Glan laser wave plate 5 and the half-slide II 6, then enters the dichroic mirror 7 for high reflection, and the femtosecond laser beam 2 after high reflection is focused in the optical fiber 12 to be etched through the focusing lens 8, so as to etch the optical fiber 12 to be etched. It is worth noting that the glan laser wave plate 5 is arranged in the middle of the half-wave plate I4 and the half-slide II 6, and the focal centers of the half-wave plate I4, the glan laser wave plate 5 and the half-slide II 6 are on the same horizontal plane.
In the visible light real-time imaging system, the visible light real-time imaging system includes a visible light source 9 and a CCD camera 11, wherein the visible light source 9 emits a visible light beam 10 of near parallel light, the visible light source 9 may be a visible light LED, or may be a wide spectrum visible light source, such as: a halogen light source. The CCD camera 11 may be an industrial or scientific high resolution color or black and white camera.
The visible light beam 10 passes through the optical fiber 12 to be etched and enters the focusing lens 8, the visible light beam 10 is focused in the dichroic mirror 7 through the focusing of the focusing lens 8, and enters the CCD camera 11 through the high transmittance of the dichroic mirror 7, and an imaging picture of the optical fiber 12 to be etched is obtained in the CCD camera 11.
Referring to fig. 3, in the positioning module, the positioning module includes a three-dimensional displacement platform 16, an optical fiber clamp 13 and a U-shaped groove assembly 14 are disposed on the three-dimensional displacement platform 16, wherein the U-shaped groove assembly 14 is composed of a U-shaped groove 14.1, a cover glass 14.2 and an index matching fluid 14.3 from top to bottom. Specifically, a U-shaped groove assembly 14 is fixed on a three-dimensional displacement platform 16 through a clamp 15 of a three-dimensional adjusting frame, an optical fiber 12 to be etched is placed in the middle of the U-shaped groove 14.1 through an optical fiber clamp 13, the inner side structure of the U-shaped groove 14.1 can be a U-shaped structure, a V-shaped structure, or other structures, the inner diameter of the U-shaped groove is not smaller than the outer diameter of the optical fiber 12 to be etched, a refractive index matching liquid 14.3 is arranged between the inner sides of the optical fiber 12 to be etched and the U-shaped groove 14.1, a cover glass 14.2 is arranged on the upper surface of the U-shaped groove 14.1, and the thickness range: 80-150 microns. Wherein the refractive index range of the refractive index matching fluid 14.3 is as follows: 1.33-2.5, can be edible oil, index matching oil for commercial use or scientific research, and the like. The control precision of the three-dimensional displacement platform 16 is 1 nanometer, and the moving speed range is as follows: 0.0001 mm/s-10 m/s.
In the image recognition program control module, the image recognition program control module comprises a computer 17 and a data line 18, and the computer 17 is electrically connected with the electronic shutter 3, the CCD camera 11 and the three-dimensional displacement platform 16 through the data line 18.
The embodiment also provides a preparation method of the femtosecond laser direct-writing fiber grating preparation device based on machine learning image recognition, and the preparation method specifically comprises the following steps:
step S1: the preparation work of the femtosecond laser incident light path and the visible light imaging light path is completed, namely the femtosecond laser direct writing light path system and the visible light real-time imaging system are used for enabling the femtosecond laser incident light path and the visible light imaging light path to be coaxial and confocal, and the preparation method specifically comprises the following steps:
step S1.1: the femtosecond laser beam 2 vertically passes through the electronic shutter 3 and the center of the combined lens, and simultaneously enters the center of the dichroic mirror 7 at an incidence angle of 45 degrees, and after passing through the dichroic mirror 7, the femtosecond laser beam 2 vertically enters the XY plane of the three-dimensional displacement platform 16 and vertically enters the focusing lens 8.
Step S1.2: the visible light beam 10 passes through a focusing lens 8 and a dichroic mirror 7, and then enters the center of an imaging chip of a CCD camera 11 through vertical incidence.
Step S2: opening the electronic shutter 3, the near infrared femtosecond laser or amplifier 1 emits the femtosecond laser beam 2, simultaneously opening the imaging software in the CCD camera 11 through the computer 17, starting the real-time capture mode, adjusting the power of the near infrared femtosecond laser or amplifier 1 from small to large until a bright light spot is seen in the imaging software, simultaneously marking the position of the bright light spot on the display screen of the computer 17, wherein the marked position indicates the imaging position of the focus after the femtosecond laser beam 2 passes through the focusing lens 8.
Step S3: closing the electronic shutter 3, adjusting the position of the three-dimensional displacement platform 16, so that when the visible light source 9 emits the visible light beam 10, an imaging picture is obtained in the CCD camera 11, and it is confirmed whether the position of the bright light spot marked in step S2 is located at the center of the fiber core of the imaging picture, and if so, the position is kept unchanged.
If the optical fiber 12 to be etched is not located in the imaging picture, the Y axis of the three-dimensional displacement platform 16 is moved with the accuracy of 1 nanometer until the marked bright light spot position is located at the center position of the fiber core 12.1 of the imaging picture, and then the imaging picture of the optical fiber 12 to be etched in the center of the fiber core 12.1 and the characteristic curve of the optical fiber to be etched are obtained.
Step S4: the central axis track of the optical fiber in the area of the optical fiber grating 19 to be etched is searched.
Step S5: and returning the X axis, the Y axis and the Z axis of the three-dimensional displacement platform 16 to the starting position of the fiber bragg grating 19 to be etched, setting the X axis moving speed of the three-dimensional displacement platform 16, and setting the Y axis displacement and the Z axis displacement of the three-dimensional displacement platform 16 according to the optical fiber central axis track obtained in the step S4.
In this embodiment, the fiber bragg grating feature formula is specifically as follows:
m·λFBG＝2·neff·Λ
wherein: m is the order of the fiber Bragg grating, lambdaFBGIs the central wavelength, n, of a fiber Bragg gratingeffand the lambda is the effective refractive index of the optical fiber to be etched, and the lambda is the period of the fiber Bragg grating.
Specifically, the fiber bragg grating period Λ is specifically:
Λ＝v/f
wherein: Λ is the fiber Bragg grating period, v is the X-axis moving speed of the fiber to be etched along the three-dimensional displacement platform, and f is the repetition frequency of the femtosecond laser.
Step S6: setting the output power of a near-infrared femtosecond laser or an amplifier 1, opening the electronic shutter 3, starting an engraving program until the X axis of the three-dimensional displacement platform 16 reaches the end position of the fiber bragg grating 19 to be engraved, closing the electronic shutter 3, and finishing the preparation of the fiber bragg grating 19 to be engraved.
After the fiber grating is prepared, the reflection spectrum and the transmission spectrum of the prepared fiber grating are tested by a spectrometer, and the appearance, the track and the like of the prepared grating in a fiber core are detected by an optical microscope, so that the characterization of the fiber grating is completed.
Referring to fig. 4, where the incident femtosecond laser single pulse energy of the G652D fiber grating is 200nJ, the incident femtosecond laser single pulse energy of the UHNA3 fiber grating is 86nJ, and the X-axis moving speed v is 1.08 mm/sec. Under the conditions, a uniform bragg fiber grating with the length of 50 mm is prepared, and transmission spectra measured with the wavelength precision of 0.02nm are shown in fig. 5 and 6, and it can be seen from the figure that the central wavelength of the G652D fiber grating is 1556.82nm, the central wavelength reflectivity of the grating is 99.98%, the central wavelength of the UHNA3 fiber grating is 1564.85nm, and the central wavelength reflectivity of the grating is 99.76%.
The present invention and its embodiments have been described in an illustrative manner, and not in a limiting sense, and it is to be understood that only one of the embodiments of the invention has been shown in the drawings and that the actual construction and process are not limited thereto. Therefore, if the person skilled in the art receives the teaching of the present invention, the technical scheme and the embodiments similar to the above technical scheme are not creatively designed without departing from the spirit of the present invention, and all of the technical scheme and the embodiments belong to the protection scope of the present invention.
Claims (8)
1. The femtosecond laser direct writing fiber grating preparation device based on machine learning image recognition is characterized by comprising a femtosecond laser direct writing light path system, a visible light real-time imaging system, a positioning module and an image recognition program control module, wherein the femtosecond laser direct writing light path system, the visible light real-time imaging system and the positioning module are electrically connected with the image recognition program control module, the image recognition program control module positions an optical fiber (12) to be engraved through the positioning module according to a picture to be engraved of the optical fiber (12), the positioned optical fiber (12) to be engraved is engraved through the femtosecond laser direct writing light path system, and the imaged picture of the engraved optical fiber (12) to be engraved is observed through the visible light real-time imaging system.
2. The femtosecond laser direct-writing fiber grating preparation device based on machine learning image recognition is characterized in that the optical fiber (12) to be engraved comprises a fiber core (12.1), a cladding (12.2) and a coating layer (12.3), the fiber core (12.1) is arranged in the center of the optical fiber (12) to be engraved, the cladding (12.2) is arranged outside the fiber core (12.1), the coating layer (12.3) is arranged outside the cladding (12.2), and the material refractive index ranges of the fiber core (12.1) and the cladding (12.2) are: 1.44-2.5.
3. The femtosecond laser direct-writing fiber grating preparation device based on machine learning image recognition according to claim 1 or 2, wherein the femtosecond laser direct-writing optical path system comprises a near-infrared femtosecond laser or amplifier (1), an electronic shutter (3), a combined lens, a dichroic mirror (7) and a focusing lens (8), the near-infrared femtosecond laser or amplifier (1) emits a femtosecond laser beam (2), the femtosecond laser beam (2) is transmitted into the dichroic mirror (7) through the electronic shutter (3) and the combined lens for high reflection, and the femtosecond laser beam (2) after high reflection is focused in an optical fiber (12) to be etched through the focusing lens (8) to etch the optical fiber (12) to be etched.
4. The femtosecond laser direct-writing fiber grating preparation device based on machine learning image recognition is characterized in that the combined lens comprises a half-wave plate I (4), a Glan laser wave plate (5) and a half-glass plate II (6), wherein the Glan laser wave plate (5) is arranged in the middle of the half-wave plate I (4) and the half-glass plate II (6), and the focal centers of the half-wave plate I (4), the Glan laser wave plate (5) and the half-glass plate II (6) are on the same horizontal plane.
5. The femtosecond laser direct-writing fiber grating preparation device based on machine learning image recognition according to claim 3, wherein the visible light real-time imaging system comprises a visible light source (9) and a CCD camera (11), the visible light source (9) emits a visible light beam (10), the visible light beam (10) passes through the fiber to be engraved (12) and enters a focusing lens (8), the visible light beam is focused in a dichroic mirror (7) through the focusing lens (8), and simultaneously enters the CCD camera (11) through high transmittance of the dichroic mirror (7), and an imaging picture of the fiber to be engraved (12) is obtained in the CCD camera (11).
6. The femtosecond laser direct-writing fiber grating preparation device based on machine learning image recognition according to claim 5, wherein the positioning module comprises a three-dimensional displacement platform (16), a U-shaped groove assembly (14) is fixed on the three-dimensional displacement platform (16) through a clamp (15) of a three-dimensional adjusting frame, and the optical fiber (12) to be engraved is arranged inside the U-shaped groove assembly (14) through a fiber clamp (13).
7. The femtosecond laser direct-writing fiber grating preparation device based on machine learning image recognition according to claim 6, wherein the U-shaped groove assembly (14) comprises a U-shaped groove (14.1), a cover glass (14.2) and an index matching fluid (14.3), the optical fiber (12) to be etched is placed in the middle of the U-shaped groove (14.1), the index matching fluid (14.3) is arranged between the optical fiber (12) to be etched and the inner side of the U-shaped groove (14.1), and the cover glass (14.2) is arranged on the upper surface of the U-shaped groove (14.1).
8. The femtosecond laser direct-writing fiber grating preparation device based on machine learning image recognition according to claim 6, wherein the image recognition program control module comprises a computer (17) and a data line (18), and the computer (17) is electrically connected with the electronic shutter (3), the CCD camera (11) and the three-dimensional displacement platform (16) through the data line (18).
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| CN112636139A (en) * | 2020-12-04 | 2021-04-09 | 北京信息科技大学 | Femtosecond laser direct-writing core cladding composite FBG erbium-doped fiber laser |
| CN112958926A (en) * | 2021-02-03 | 2021-06-15 | 西北工业大学 | Optical fiber clamping system, control method and application |
| CN113009618A (en) * | 2021-03-23 | 2021-06-22 | 吉林大学 | Method for preparing chirped fiber grating by femtosecond laser direct writing technology |
| CN113655562A (en) * | 2021-08-11 | 2021-11-16 | 深圳市畅格光电有限公司 | Automatic feeding device for femtosecond laser writing fiber bragg grating and writing processing steps |
| WO2024022871A1 (en) | 2022-07-29 | 2024-02-01 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Optical fibre comprising a bragg grating |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN112636139A (en) * | 2020-12-04 | 2021-04-09 | 北京信息科技大学 | Femtosecond laser direct-writing core cladding composite FBG erbium-doped fiber laser |
| CN112958926A (en) * | 2021-02-03 | 2021-06-15 | 西北工业大学 | Optical fiber clamping system, control method and application |
| CN113009618A (en) * | 2021-03-23 | 2021-06-22 | 吉林大学 | Method for preparing chirped fiber grating by femtosecond laser direct writing technology |
| CN113655562A (en) * | 2021-08-11 | 2021-11-16 | 深圳市畅格光电有限公司 | Automatic feeding device for femtosecond laser writing fiber bragg grating and writing processing steps |
| WO2024022871A1 (en) | 2022-07-29 | 2024-02-01 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Optical fibre comprising a bragg grating |
| FR3138531A1 (en) | 2022-07-29 | 2024-02-02 | Commissariat à l'Energie Atomique et aux Energies Alternatives | Optical fiber comprising a Bragg grating |
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Assignee: Xuzhou Zhiguang Information Technology Co.,Ltd. Assignor: Jiangsu Normal University Contract record no.: X2023980047341 Denomination of utility model: Fabrication device of femtosecond laser direct writing fiber grating based on machine learning image recognition Granted publication date: 20200929 License type: Common License Record date: 20231118 |