A method and device for direct writing high-perspective photon optical path by femtosecond laser

Abstract

The present invention discloses a method and device for direct writing a high-perspective photon optical path by femtosecond laser. The method utilizes femtosecond laser direct writing technology, and through slit shaping technology and laser parameter control, realizes the circular symmetry of the cross section of the photon optical path and the adjustability of the cross-sectional size, and realizes a method for preparing a photon optical path with high perspective in a variety of commercial glasses. The action area near the laser focus realizes the modification of all positive refractive index changes, optimizes the performance of the photon optical path, realizes the effective mode matching of the photon optical path and the visible wavelength optical fiber, and at the same time, the change of all positive refractive indexes in the area near the laser focus also improves the high transparency of the photon optical path.

Description

Technical Field

[0001] The invention relates to the field of laser application technology, and in particular to a method and a device for directly writing a high-perspective photon optical path with a femtosecond laser. Background Art

[0002] With the rapid development of emerging artificial intelligence technologies, transparent screens or substrates embedded with various transparent optoelectronic components are considered to be one of the most promising solutions for realizing wearable augmented reality / virtual reality devices. Among the many embedding solutions, the use of femtosecond laser direct writing technology to manufacture photonic devices in transparent materials has irreplaceable advantages.

[0003] Femtosecond lasers have a narrow pulse width, and the peak power density of the pulses of femtosecond lasers is large enough, which is the basis for using femtosecond lasers for three-dimensional processing. In the process of using femtosecond lasers for processing, since the energy near the focus of the femtosecond laser is very high, a considerable amount of energy is injected into the laser focus located inside the material in a very short time. A complex nonlinear interaction will occur between the laser and the processed material, forming a local modification of the material, causing a change in the local refractive index of the material, and forming an optical waveguide. However, using conventional laser focusing schemes, the longitudinal dimension of the focused spot will be larger than the lateral dimension, and the resulting waveguide cross-section is a flat and long structure elongated along the laser direction, with a large aspect ratio, which is not conducive to the production of symmetrical cross-section waveguides. The cross-sectional shape of the waveguide determines the mode field distribution of the guided mode. A waveguide with a symmetrical cross-section can achieve effective mode matching with the optical fiber, reduce losses, and improve the performance of the optical waveguide.

[0004] Furthermore, under conventional laser focusing schemes, in the laser irradiation area, the waveguide area with a positive refractive index change is often accompanied by a damaged area with a negative refractive index change. From a microstructural point of view, the negative refractive index change area contains a large number of irregular cracks and nano-void structures, which may cause the scattering of the guided light, thereby increasing the waveguide transmission loss. Especially for short-wavelength waveguides, such as visible light waveguides, the light scattering caused by the negative refractive index area is more obvious. Therefore, the generation of negative refractive index areas must be avoided as much as possible when laser direct writing low-scattering waveguides. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a method for femtosecond laser direct writing of high-perspective photon optical paths. The method utilizes femtosecond laser direct writing technology, through slit shaping technology and control of laser parameters, to achieve the circular symmetry of the cross-section of the photon optical path and the adjustability of the cross-sectional size, thereby realizing a method for preparing photon optical paths with high perspective in a variety of commercial glasses.

[0006] The present invention is achieved through the following technical solutions:

[0007] A method for femtosecond laser direct writing of a high-perspective photon optical path comprises the following steps:

[0008] (1) Using a glass sample to prepare a desired photon optical path using a femtosecond laser direct writing technique, and using a slit shaping technique to adjust the cross-sectional size of the photon optical path obtained by the femtosecond laser direct writing;

[0009] (2) Select the slit width according to the refractive index of the glass and the numerical aperture of the objective lens, and place the appropriate slit in front of the focusing lens;

[0010] (3) The light beam emitted by the laser is shaped by a suitable slit selected in step (2), and the shaped light beam is focused by a lens to obtain a light spot, and an optical waveguide is obtained by direct writing with a femtosecond laser inside the glass sample; the light spot is an elliptical Gaussian type, and the ratio of the transverse dimension to the longitudinal dimension of the cross section of the photon optical path obtained by femtosecond laser processing, i.e., the aspect ratio, is adjusted by selecting slits of different widths;

[0011] (4) The moving speed of the translation stage and the interval between the photon optical paths are controlled by setting the moving speed value, the moving direction, and the interval value of the photon optical path. The power of the laser is adjusted to adjust the parameters of the laser processing photon optical path, thereby controlling the cross-sectional size of the prepared optical waveguide. The processing parameters mainly include the movement of the translation stage, i.e., the scanning speed, and the parameter setting of the laser. When the transverse dimension and the longitudinal dimension of the cross section of the prepared optical waveguide are equal, an optical waveguide with a circularly symmetric cross section and a completely positive refractive index distribution is obtained.

[0012] Furthermore, in step (1), the cross-sectional dimensions of the photon optical path obtained by femtosecond laser direct writing are regulated by slit shaping technology, wherein the width of the slit varies according to the numerical aperture of the objective lens, the numerical aperture varies in the range of 0.2-0.9NA, and the slit width ranges from 0.1-1.2 mm.

[0013] Specifically, the laser in step (2) uses a variety of output wavelengths, including but not limited to 355nm, 515nm and 1030nm; the pulse width range is 40fs-10ps; the high repetition frequency range is 200kHz-10MHZ; the power range is 10mW-10W; the polarization includes linear polarization and circular polarization; the femtosecond laser or picosecond laser uses a focusing objective with different numerical apertures to focus the laser to different depths inside the glass; the focusing depth range is 5-1000μm; and the aperture value range is 0.2<NA<0.9.

[0014] Specifically, the commercial glass includes but is not limited to any one of Gorilla, K9, Eagle and FS-7980.

[0015] Furthermore, the movement of the translation stage in step (4) is to adjust the three-dimensional spatial path and speed of the scan by means of the translation stage, wherein the scanning speed ranges from 1 to 100 mm / s.

[0016] Furthermore, in step (4), the power adjustment range of the laser is 200nJ-5000nJ.

[0017] Furthermore, the entire positive refractive index of the laser focus action area changes, so that the processed three-dimensional photon optical path has high perspective in a visible light environment.

[0018] Furthermore, in step (4), the cross-sectional diameter of the waveguide is in the range of 4-22 μm, and when the cross-sectional shape of the waveguide is observed under a microscope, the ellipticity of the corresponding cross-sectional morphology is greater than 95%.

[0019] A femtosecond laser direct writing high-perspective photon optical path device, the device comprises the following modules:

[0020] Preparation and control module: using a glass sample to prepare the required photon optical path by femtosecond laser direct writing technology, and using slit shaping technology to control the cross-sectional size of the photon optical path obtained by femtosecond laser direct writing;

[0021] Place the module: select the slit width according to the refractive index of the glass and the numerical aperture of the objective lens, and place the appropriate slit in front of the focusing lens;

[0022] Beam shaping module: the light beam emitted by the laser is shaped by the appropriate slit selected in step (2), and the shaped light beam is focused by a lens to obtain a light spot, which is directly written to the optical waveguide inside the glass sample by a femtosecond laser; the light spot is an elliptical Gaussian type, and the ratio of the transverse dimension to the longitudinal dimension of the cross section of the photon optical path obtained by femtosecond laser processing, i.e., the aspect ratio, is adjusted by selecting slits of different widths;

[0023] Obtaining an optical waveguide module: controlling the moving speed of the translation stage and the interval between the photon optical paths by setting the moving speed value, the moving direction, and the interval value of the photon optical path, adjusting the power of the laser to adjust the parameters of the laser-processed photon optical path, and thus controlling the cross-sectional dimensions of the prepared optical waveguide. The processing parameters mainly include the movement of the translation stage, i.e., the scanning speed, and the parameter settings of the laser. When the transverse dimension and the longitudinal dimension of the cross section of the prepared optical waveguide are equivalent, an optical waveguide with a circularly symmetric cross section and a completely positive refractive index distribution is obtained.

[0024] Specifically, the transverse dimension and the longitudinal dimension of the cross section of the optical waveguide in the optical waveguide acquisition module are equivalent, specifically, the ratio of the transverse dimension to the longitudinal dimension of the cross section is 0.95:1-1:1.

[0025] The beneficial effects of the present invention are as follows:

[0026] (1) Compared with traditional methods of preparing optical waveguides such as photolithography and ion implantation, femtosecond laser direct writing is simple, efficient, and has a fast direct writing speed.

[0027] (2) Compared with conventional femtosecond laser processing without beam shaping, the cross-section of the optical waveguide processed in the sample after slit shaping and laser focusing shows better circular symmetry when observed under a microscope. The size of the cross-section and the distribution of the refractive index can be controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the slit shaping principle of the present invention;

[0029] Figure 2 It is a schematic diagram of the change of the photon optical path cross section with the processing parameters of the present invention;

[0030] Figure 3 The figures are a demonstration of the high-perspective photon optical path of the present invention and a scattering test diagram; wherein (a) is a diagram showing the scattering of green light through the high-perspective photon optical path and the ordinary photon optical path; (b) is a diagram showing the scattering of red light through the high-perspective photon optical path and the ordinary photon optical path;

[0031] Figure 4 This is a demonstration diagram of the high-perspective photon optical path of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0033] A method for femtosecond laser direct writing of a high-perspective photon optical path comprises the following steps:

[0034] (1) Using a glass sample to prepare a desired photon optical path using a femtosecond laser direct writing technique, and using a slit shaping technique to adjust the cross-sectional size of the photon optical path obtained by the femtosecond laser direct writing;

[0035] (2) Select the slit width according to the refractive index of the glass and the numerical aperture of the objective lens, and place the appropriate slit in front of the focusing lens;

[0036] (3) The light beam emitted by the laser is shaped by a suitable slit selected in step (2), and the shaped light beam is focused by a lens to obtain a light spot, and an optical waveguide is obtained by direct writing with a femtosecond laser inside the glass sample; the light spot is an elliptical Gaussian type, and the ratio of the transverse dimension to the longitudinal dimension of the cross section of the photon optical path obtained by femtosecond laser processing, i.e., the aspect ratio, is adjusted by selecting slits of different widths;

[0037] (4) The moving speed of the translation stage and the interval between the photon optical paths are controlled by setting the moving speed value, the moving direction, and the interval value of the photon optical path. The power of the laser is adjusted to adjust the parameters of the laser processing photon optical path, thereby controlling the cross-sectional size of the prepared optical waveguide. The processing parameters mainly include the movement of the translation stage, i.e., the scanning speed, and the parameter setting of the laser. When the transverse dimension and the longitudinal dimension of the cross section of the prepared optical waveguide are equal, an optical waveguide with a circularly symmetric cross section and a completely positive refractive index distribution is obtained.

[0038] Furthermore, in step (1), the cross-sectional dimensions of the photon optical path obtained by femtosecond laser direct writing are regulated by slit shaping technology, wherein the width of the slit varies according to the numerical aperture of the objective lens, the numerical aperture varies in the range of 0.2-0.9NA, and the slit width ranges from 0.1-1.2 mm.

[0039] Specifically, the laser in step (2) uses a variety of output wavelengths, including but not limited to 355nm, 515nm and 1030nm; the pulse width range is 40fs-10ps; the high repetition frequency range is 200kHz-10MHZ; the power range is 10mW-10W; the polarization includes linear polarization and circular polarization; the femtosecond laser or picosecond laser uses a focusing objective with different numerical apertures to focus the laser to different depths inside the glass; the focusing depth range is 5-1000μm; and the aperture value range is 0.2<NA<0.9.

[0040] Specifically, the commercial glass includes but is not limited to any one of Gorilla, K9, Eagle and FS-7980.

[0041] Furthermore, the movement of the translation stage in step (4) is to adjust the three-dimensional spatial path and speed of the scan by means of the translation stage, wherein the scanning speed ranges from 1 to 100 mm / s.

[0042] Furthermore, in step (4), the power adjustment range of the laser is 200nJ-5000nJ.

[0043] Furthermore, the entire positive refractive index of the laser focus action area changes, so that the processed three-dimensional photon optical path has high perspective in a visible light environment.

[0044] Furthermore, in step (4), the cross-sectional diameter of the waveguide is in the range of 4-22 μm, and when the cross-sectional shape of the waveguide is observed under a microscope, the ellipticity of the corresponding cross-sectional morphology is greater than 95%.

[0045] Another aspect of the present invention is a femtosecond laser direct writing high-perspective photon optical path device, the device comprising the following modules:

[0046] Preparation and control module: using a glass sample to prepare the required photon optical path by femtosecond laser direct writing technology, and using slit shaping technology to control the cross-sectional size of the photon optical path obtained by femtosecond laser direct writing;

[0047] Place the module: select the slit width according to the refractive index of the glass and the numerical aperture of the objective lens, and place the appropriate slit in front of the focusing lens;

[0048] Beam shaping module: the light beam emitted by the laser is shaped by the appropriate slit selected in step (2), and the shaped light beam is focused by a lens to obtain a light spot, which is directly written to the optical waveguide inside the glass sample by a femtosecond laser; the light spot is an elliptical Gaussian type, and the ratio of the transverse dimension to the longitudinal dimension of the cross section of the photon optical path obtained by femtosecond laser processing, i.e., the aspect ratio, is adjusted by selecting slits of different widths;

[0049] Obtaining an optical waveguide module: controlling the moving speed of the translation stage and the interval between the photon optical paths by setting the moving speed value, the moving direction, and the interval value of the photon optical path, adjusting the power of the laser to adjust the parameters of the laser-processed photon optical path, and thus controlling the cross-sectional dimensions of the prepared optical waveguide. The processing parameters mainly include the movement of the translation stage, i.e., the scanning speed, and the parameter settings of the laser. When the transverse dimension and the longitudinal dimension of the cross section of the prepared optical waveguide are equivalent, an optical waveguide with a circularly symmetric cross section and a completely positive refractive index distribution is obtained.

[0050] Specifically, the transverse dimension and the longitudinal dimension of the cross section of the optical waveguide in the optical waveguide acquisition module are equivalent, specifically, the ratio of the transverse dimension to the longitudinal dimension of the cross section is 0.95:1-1:1.

[0051] Embodiments of the present invention are as follows:

[0052] Example 1

[0053] like Figure 1 As shown, this embodiment adopts the slit shaping technology, and in this embodiment, Corning (Eagle) glass is used as the material for femtosecond laser direct writing.

[0054] The femtosecond laser parameters used in Example 1 are: central wavelength 1030nm, pulse width 216fs, repetition frequency 1MHz. The focusing lens parameters are: magnification 50×, numerical aperture NA=0.55. The energy deposited on the sample is 600nJ through a 0.1-1μJ continuous attenuator, the scanning speed range is 1.5-40mm / s, and the focus depth is 150μm. The slit width is 0.4mm, and the schematic diagram of the slit shaping principle is as follows Figure 1 shown.

[0055] The specific steps are:

[0056] 1) Turn on the air compressor and other basic equipment, fix the Eagle glass on the stage, observe through the microscope, adjust the field of view, find the edge of the glass, adjust the position of the Eagle glass, and ensure that the edge of the glass is perpendicular to the movement direction of the translation stage.

[0057] 2) After adjusting the position of the sample, turn on the laser, set the laser parameters, excite the laser, and test the output light power.

[0058] 3) The movement of the three-dimensional translation stage is controlled by software programming. First, the focus of the laser is sunk to 150μm below the upper surface of the sample. The movement of the translation stage in the xy plane is controlled by program coding to realize the processing of the photon optical path inside the glass. The movement speed of the translation stage is changed to 1.5mm / s, 2.5mm / s, 5mm / s, 10mm / s, 20mm / s and 40mm / s in sequence. This realizes femtosecond laser direct writing of photon optical paths with different scanning speeds at the same power.

[0059] Example 2

[0060] In this embodiment, Corning Gorilla Glass is used as the material for femtosecond laser direct writing.

[0061] The femtosecond laser parameters used in Example 2 are: central wavelength 1030nm, pulse width 216fs, repetition frequency 1MHz. The focusing lens parameters are: magnification 50×, numerical aperture NA=0.55. The energy deposited on the sample is finely controlled to vary from 400nJ to 700nJ via a 0.1-1μJ continuous attenuator, the scanning speed is 5mm / s, and the focusing depth is 150μm. The slit width is 0.5mm; the laser power adjustment range is 200nJ-5000nJ.

[0062] In addition, in the above-mentioned embodiment, the numerical aperture range can be 0.2-0.9NA, the slit width range can be 0.1-1.2mm, and the laser adopts multiple output wavelengths, including but not limited to 355nm, 515nm and 1030nm; the pulse width range can be 40fs-10ps; the high repetition frequency range can be 200kHz-10MHZ; the power range can be 10mW-10W; the focusing depth range can be 5-1000μm; and the aperture value range can be 0.2<NA<0.9. Within this range, the present invention can be implemented.

[0063] The specific steps are:

[0064] 1) Turn on the air compressor and other basic equipment, fix the Gorilla glass on the stage, observe through the microscope, adjust the field of view, find the edge of the glass, and adjust the position of the Gorilla glass to ensure that the edge of the glass is perpendicular to the movement direction of the stage.

[0065] 2) After adjusting the position of the sample, turn on the laser, set the laser parameters, excite the laser, and test the output light power.

[0066] 3) The movement of the three-dimensional translation stage is controlled by software programming. First, the focus of the laser is sunk to 150 μm below the upper surface of the sample. The movement of the translation stage in the xy plane is controlled by program coding to realize the processing of the photon optical path inside the glass. The scanning speed is controlled to be constant. A fine attenuation controller of 0.1-1 μJ is used to realize femtosecond laser direct writing of the photon optical path under different laser energies at the same scanning speed.

[0067] The software programming is used to control the movement of the three-dimensional translation stage, specifically: when the speed is defined as 1.5 mm / s, the translation stage moves 14 mm along the positive direction of the X axis to obtain a photon optical path. Then the translation stage moves 0.1 mm along the negative direction of the Y axis, indicating that the interval with the next photon optical path is 0.1 mm.

[0068] The speed is defined as 2.5 mm / s, the stage moves 14 mm in the negative X direction, and then moves 0.1 mm in the negative Y direction, indicating that the interval with the next photon optical path is 0.1 mm.

[0069] The speed is defined as 5 mm / s, the stage moves 14 mm in the positive X direction, and then moves 0.1 mm in the negative Y direction, indicating that the interval with the next photon optical path is 0.1 mm.

[0070] The speed is defined as 10 mm / s, the stage moves 14 mm in the negative X direction, and then moves 0.1 mm in the negative Y direction, indicating that the interval with the next photon optical path is 0.1 mm.

[0071] The speed is defined as 20 mm / s, the stage moves 14 mm in the positive X direction, and then moves 0.1 mm in the negative Y direction, indicating that the interval with the next photon optical path is 0.1 mm.

[0072] The speed is defined as 40 mm / s, the translation stage moves 14 mm in the negative X direction, and the program ends.

[0073] Implementation cases show that the present invention can prepare photon optical paths with good cross-sectional symmetry in a variety of commercial glasses using femtosecond laser direct writing technology.

[0074] In the above two embodiments, photon optical paths were prepared in different glasses using different femtosecond laser direct writing parameters. It was found that the purpose of controlling the cross-sectional size of the photon optical path can be achieved by adjusting the scanning speed and the energy of the laser. The trend of the cross-sectional size change caused by the increase in scanning speed is similar to the effect brought about by reducing the laser power. More detailed results are shown in Figure 2 As shown, from bottom to top represents the increase of laser energy, and from left to right represents the increase of scanning speed. It can be found that at the same scanning speed, as the laser energy increases, the cross-sectional size gradually increases from bottom to top. Similarly, under the premise of fixed laser energy, increasing the scanning speed, the cross-sectional size decreases from left to right.

[0075] In addition, the photon optical path in the glass is used to demonstrate the high-perspective photon optical path, such as Figure 4 As shown, the left side demonstrates the coupling of the photon optical path prepared by the slit shaping technology with the red and green visible wavelength optical fibers respectively, and the right side demonstrates the coupling of the photon optical path prepared without the slit shaping technology with the red and green visible wavelength optical fibers respectively. It can be found that after the photon optical path prepared without the slit shaping technology is coupled with the red and green visible wavelength optical fibers respectively, an obvious optical path will be shown in the glass, while the photon optical path prepared by the slit shaping technology is coupled with the red and green visible wavelength optical fibers respectively, and the laser passes through the glass with almost no trace, showing high perspective. In addition, we also tested the scattering of light. The results of the green and red light scattering intensity tests are shown in Figure 3 In (a) and (b), it can be seen that whether it is green light or red light, the photon optical path prepared by slit shaping technology shows weak scattering intensity, which is consistent with the phenomenon we observed.

[0076] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for femtosecond laser direct writing of high-perspective photon optical paths, characterized in that: The steps include: (1) Using a glass sample to prepare a desired photon optical path using a femtosecond laser direct writing technique, and using a slit shaping technique to adjust the cross-sectional size of the photon optical path obtained by the femtosecond laser direct writing; (2) Select the slit width according to the refractive index of the glass and the numerical aperture of the objective lens, and place the appropriate slit in front of the focusing lens; (3) The light beam emitted by the laser is shaped by a suitable slit selected in step (2), and the shaped light beam is focused by a lens to obtain a light spot, and an optical waveguide is obtained by direct writing with a femtosecond laser inside the glass sample; the light spot is an elliptical Gaussian type, and the ratio of the transverse dimension to the longitudinal dimension of the cross section of the photon optical path obtained by femtosecond laser processing, i.e., the aspect ratio, is adjusted by selecting slits of different widths; (4) The moving speed of the translation stage and the interval between the photon optical paths are controlled by setting the moving speed value, the moving direction, and the interval value of the photon optical path. The power of the laser is adjusted to adjust the parameters of the laser processing photon optical path, thereby controlling the cross-sectional size of the prepared optical waveguide. The processing parameters mainly include the movement of the translation stage, i.e., the scanning speed, and the parameter setting of the laser. When the transverse dimension and the longitudinal dimension of the cross section of the prepared optical waveguide are equal, an optical waveguide with a circularly symmetric cross section and a completely positive refractive index distribution is obtained.

2. The method of femtosecond laser direct writing high-perspective photon optical path according to claim 1, characterized in that: In the step (1), the cross-sectional dimensions of the photon optical path obtained by direct writing with a femtosecond laser are regulated by using a slit shaping technique, wherein the width of the slit varies according to the numerical aperture of the objective lens, the numerical aperture varies in the range of 0.2-0.9NA, and the slit width ranges from 0.1-1.2 mm.

3. The method for femtosecond laser direct writing of high-perspective photon optical path according to claim 1, characterized in that: The laser in step (2) adopts a plurality of output wavelengths, including but not limited to 355nm, 515nm and 1030nm; the pulse width range is 40fs-10ps; the high repetition frequency range is 200kHz-10MHZ; the power range is 10mW-10W; the polarization includes linear polarization and circular polarization; the femtosecond laser or picosecond laser adopts focusing objective lenses with different numerical apertures to focus the laser to different depths inside the glass; the focusing depth range is 5-1000μm; The aperture value range is 0.2<NA<0.

9.

4. The method for femtosecond laser direct writing of high-perspective photon optical path according to claim 1, characterized in that: The commercial glass is any one including but not limited to Gorilla, K9, Eagle and FS-7980.

5. The method for femtosecond laser direct writing high-perspective photon optical path according to claim 1, characterized in that: The movement of the translation stage in step (4) is to adjust the three-dimensional space path and speed of the scan by means of the translation stage, wherein the scanning speed ranges from 1 to 100 mm / s.

6. The method of femtosecond laser direct writing high-perspective photon optical path according to claim 1, characterized in that: The power adjustment range of the laser in step (4) is 200nJ-5000nJ.

7. The method for femtosecond laser direct writing high-perspective photon optical path according to claim 1, characterized in that: The laser focus action area has a total positive refractive index change, so that the processed three-dimensional photon optical path has high perspective in a visible light environment.

8. The method of femtosecond laser direct writing high-perspective photon optical path according to claim 1, characterized in that: The cross-sectional diameter of the waveguide in step (4) is in the range of 4-22 μm. When the cross section of the waveguide is observed under a microscope, the ellipticity of the corresponding cross-sectional morphology is greater than 95%.

9. A femtosecond laser direct writing high-perspective photon optical path device, characterized in that: The device includes the following modules: Preparation and control module: using a glass sample to prepare the required photon optical path by femtosecond laser direct writing technology, and using slit shaping technology to control the cross-sectional size of the photon optical path obtained by femtosecond laser direct writing; Place the module: select the slit width according to the refractive index of the glass and the numerical aperture of the objective lens, and place the appropriate slit in front of the focusing lens; Beam shaping module: the light beam emitted by the laser is shaped by the appropriate slit selected in step (2), and the shaped light beam is focused by a lens to obtain a light spot, which is directly written to the optical waveguide inside the glass sample by a femtosecond laser; the light spot is an elliptical Gaussian type, and the ratio of the transverse dimension to the longitudinal dimension of the cross section of the photon optical path obtained by femtosecond laser processing, i.e., the aspect ratio, is adjusted by selecting slits of different widths; Obtaining an optical waveguide module: controlling the moving speed of the translation stage and the interval between the photon optical paths by setting the moving speed value, the moving direction, and the interval value of the photon optical path, adjusting the power of the laser to adjust the parameters of the laser-processed photon optical path, and thus controlling the cross-sectional dimensions of the prepared optical waveguide. The processing parameters mainly include the movement of the translation stage, i.e., the scanning speed, and the parameter settings of the laser. When the transverse dimension and the longitudinal dimension of the cross section of the prepared optical waveguide are equivalent, an optical waveguide with a circularly symmetric cross section and a completely positive refractive index distribution is obtained.

10. A femtosecond laser direct writing high-perspective photon optical path device according to claim 9, characterized in that: The transverse dimension and the longitudinal dimension of the cross section of the optical waveguide in the optical waveguide acquisition module are equivalent, specifically, the ratio of the transverse dimension to the longitudinal dimension of the cross section is 0.95:1-1:1.

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