Generating device capable of simultaneously generating four spatial orthogonal modes

Abstract

The invention provides a device and a method for simultaneously generating four spatial orthogonal modes, and belongs to the technical field of optical engineering and laser. Comprising a laser source used for outputting a plane wave of a fundamental mode Gaussian beam; the mode converter is used for generating a standard HG10 mode; and the mode shaper is used for carrying out beam splitting and mode shaping on a standard HG10 mode and outputting the HG10 mode, an HG01 mode, a left-handed LG01 mode and a right-handed LG01 mode at the same time. According to the method and the device, the complexity of a traditional multi-mode generation system is remarkably simplified, and the efficiency, the stability and the flexibility of mode generation are improved. Through the innovative optical design and phase regulation technology, four spatial orthogonal modes are simultaneously generated from a single fundamental mode light beam, powerful technical support is provided for the fields of optical communication, optical information processing and the like, and wide application prospects are achieved.

Description

Technical Field

[0001] The invention relates to the fields of optical engineering and laser, and in particular to a device for generating four spatial orthogonal modes simultaneously. Background Art

[0002] In the field of optics, the Hermite-Gaussian (HG) mode and the Laguerre-Gaussian (LG) mode have shown broad application prospects in optical communications, optical information processing, quantum optics, and optical measurement. The HG mode and the LG mode represent different light field distribution characteristics, where the HG mode describes the light field in the form of a polynomial in rectangular coordinates, while the LG mode describes the light field in the form of a polynomial in polar coordinates and has orbital angular momentum, which has unique advantages in improving information transmission capacity and security.

[0003] Traditionally, methods for generating these specific modes usually involve complex optical systems, and can often only generate a single mode, such as directly outputting the HG mode through a specific laser resonant cavity design, or using spatial light modulators, spiral phase plates and other methods to convert to LG modes. These methods are not only complex and costly, but also difficult to achieve the simultaneous generation of multiple modes, limiting their potential in application scenarios that require multi-mode parallel processing. In particular, for the need to simultaneously generate HG10 mode, HG01 mode, and LG01 mode with different handedness (left-handed and right-handed), existing technologies often need to be implemented one by one through multiple independent devices or complex steps, which not only increases the complexity and uncertainty of the operation, but also reduces the overall efficiency and stability of the system. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a device for simultaneously generating four spatial orthogonal modes. Through innovative optical design and phase control technology, it realizes the simultaneous generation of four spatial orthogonal modes from a single fundamental mode light beam, providing strong technical support for optical communications, optical information processing and other fields, and has broad application prospects.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a device for generating four spatial orthogonal patterns at the same time, comprising the following:

[0006] Laser source: used to output a plane wave of fundamental mode Gaussian beam;

[0007] Mode converter: used to generate standard HG10 mode;

[0008] Mode shaper: used to split and mode shape the standard HG10 mode, and output HG10 mode, HG01 mode, left-handed LG01 mode and right-handed LG01 mode at the same time.

[0009] Preferably, the laser source, the mode converter and the mode shaper are arranged on a seismic isolation platform.

[0010] Preferably, the mode converter comprises a phase inversion plate and a mode filter cavity;

[0011] The inversion phase plate is used to convert the fundamental mode Gaussian beam into an approximate HG10 mode;

[0012] The mode filter cavity is used to filter out spurious modes and output a standard HG10 mode.

[0013] Preferably, the inversion phase plate comprises two glass plates with different fast axis directions spliced ​​together, and the transmittance of the laser is greater than 98%.

[0014] Preferably, the mode filtering cavity is a three-mirror annular cavity, including two planar cavity mirrors with a transmittance of 0.3% and a plano-concave mirror with a curvature radius of 1m and a reflectivity greater than 99.9%. The corresponding bandwidth is 600KHz and the fineness of the cavity is 1000.

[0015] Preferably, the mode shaper comprises a Dove prism, a first reflector, a second reflector, a first beam splitter, a second beam splitter, a third beam splitter and a fourth beam splitter.

[0016] Preferably, the transmittance of the Dove prism is greater than 98%, and is used to achieve the lateral spatial distribution rotation of the light field and convert the HG10 mode into the HG01 mode.

[0017] Preferably, the reflectivity of the first reflector and the second reflector to the laser is greater than 99.9%, wherein the first reflector is fixedly arranged on the piezoelectric ceramic to lock the relative phase between the HG10 mode and the HG01 mode.

[0018] Preferably, the first beam splitter, the second beam splitter, the third beam splitter and the fourth beam splitter are all 50 / 50 beam splitters, which are used to split the incident light into two beams of equal light intensity.

[0019] Beneficial effects of the present invention:

[0020] It is achieved that the above four spatial orthogonal modes are efficiently generated simultaneously from a fundamental mode light beam. The device of the present invention includes a laser source, a mode converter and a mode shaper. The laser output by the light source outputs the standard HG10 mode through the mode converter, and then is incident on the mode shaper, and after beam splitting and mode shaping, four spatial orthogonal modes are output simultaneously. The method and device of the present invention significantly simplify the complexity of the traditional multi-mode generation system and improve the efficiency, stability and flexibility of mode generation. Through innovative optical design and phase control technology, it is achieved that four spatial orthogonal modes are generated simultaneously from a single fundamental mode light beam, which provides strong technical support for the fields of optical communication, optical information processing, etc., and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only three of the drawings of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a principle block diagram of a device for simultaneously generating four spatial orthogonal modes provided by an embodiment of the present invention;

[0023] Figure 2 Schematic diagram of the optical path of a device for simultaneously generating four spatial orthogonal modes provided by an embodiment of the present invention;

[0024] Figure 3 is an intensity diagram of the HG01 mode, the HG10 mode, the left-handed LG01 mode, and the right-handed LG01 mode generated by the embodiment of the present invention;

[0025] Among them, 1. laser source; 2. mode converter; 3. mode shaper; 4. platform; 5. inversion phase plate; 6. mode filter cavity; 7. first beam splitter; 8. Dove prism; 9. second beam splitter; 10. first reflector; 11. second reflector; 12. third beam splitter; 13. fourth beam splitter; 14. HG01 mode; 15. HG10 mode; 16. left-handed LG01 mode; 17. right-handed LG01 mode. DETAILED DESCRIPTION

[0026] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The embodiments are only used to explain the present invention and do not limit the protection scope of the present invention.

[0027] Example

[0028] like Figure 1 As shown, a device for generating four spatial orthogonal modes simultaneously includes a laser source 1, a mode converter 2 and a mode shaper 3 arranged on a seismic isolation platform 4.

[0029] Laser source 1: used to output a plane wave of fundamental mode Gaussian beam;

[0030] Mode converter 2: used to generate standard HG10 mode.

[0031] The mode converter 2 includes a phase inversion plate 5 and a mode filter cavity 6;

[0032] The inversion phase plate 5 is used to convert the fundamental mode Gaussian beam into an approximate HG10 mode; the inversion phase plate 5 comprises two glass plates with different fast axis directions spliced ​​together, and the transmittance of the laser is greater than 98%.

[0033] The mode filter cavity 6 is used to filter out stray modes and output a standard HG10 mode; the mode filter cavity 6 is a three-mirror annular cavity, including two plane cavity mirrors with a transmittance of 0.3% and a plano-concave mirror with a curvature radius of 1m and a reflectivity greater than 99.9%, the corresponding bandwidth is 600KHz, and the fineness of the cavity is 1000.

[0034] Mode shaper 3: used to split and mode-shape the standard HG10 mode, and simultaneously output HG10 mode 15, HG01 mode 14, left-handed LG01 mode 16 and right-handed LG01 mode 17.

[0035] The mode shaper 3 includes a Dove prism 8 , a first reflector 10 , a second reflector 11 , a first beam splitter 7 , a second beam splitter 9 , a third beam splitter 12 and a fourth beam splitter 13 .

[0036] The transmittance of the Dove prism 8 is greater than 98%, and it is used to realize the rotation of the lateral spatial distribution of the light field and convert the HG10 mode into the HG01 mode. The reflectivity of the first reflector 10 and the second reflector 11 to the laser is greater than 99.9%, wherein the first reflector 10 is fixedly arranged on the piezoelectric ceramic to lock the relative phase of the HG10 mode and the HG01 mode. The first beam splitter 7, the second beam splitter 9, the third beam splitter 12 and the fourth beam splitter 13 are all 50 / 50 beam splitters, which are used to split the incident light into two beams of equal light intensity.

[0037] The plane wave of the fundamental mode Gaussian beam output by the laser source 1 is input into the mode converter 2. The fundamental mode Gaussian beam first passes through the inverted phase plate 5, and after phase modulation, it outputs an approximate HG10 mode, and then enters the mode filter cavity 6. The cavity length of the mode filter cavity 6 is locked by the standard PDH frequency stabilization technology, the stray mode is filtered out, and the standard HG10 mode is output. The standard HG10 mode enters the mode shaper 3, and is divided into two paths by the first beam splitter. One path passes through the Dove prism 8 to realize the rotation of the lateral spatial distribution of the light field and is converted into the HG01 mode. After the second beam splitter 9, the transmission part outputs the HG01 mode 14, and the reflection part interferes with the other light field. The other path passes through the third beam splitter 12, and the transmission part outputs the HG10 mode 15, and the reflection part interferes with the light field reflected by the second beam splitter 9 at the fourth beam splitter 13. The relative phase of the HG10 mode and the HG01 mode is precisely controlled to be π / 2 by the first reflector 10, and the left-handed LG01 mode 16 and the right-handed LG01 mode 17 are output through the reflection and transmission parts of the fourth beam splitter 13. The light field intensity diagram obtained by the camera.

[0038] like Figure 3 As shown, the intensity diagrams of the output HG01 mode 14, HG10 mode 15, left-handed LG01 mode 16 and right-handed LG01 mode 17 generated in the embodiment of the present invention. Among them, (a) represents the intensity diagram of HG10 mode 15, (b) represents the intensity diagram of HG01 mode 14, (c) represents the intensity diagram of left-handed LG01 mode 16, and (d) represents the intensity diagram of right-handed LG01 mode 17. The results show that the device of the present invention can generate four spatial orthogonal modes at the same time, verifying the effectiveness of our method.

[0039] The above four spatial orthogonal modes are efficiently generated simultaneously from a fundamental mode light beam. The device of the present invention comprises a laser source 1, a mode converter 2 and a mode shaper 3. The laser outputted by the light source outputs a standard HG10 mode through the mode converter 2, and then is incident on the mode shaper 3, and after beam splitting and mode shaping, four spatial orthogonal modes are outputted simultaneously.

[0040] The method and device of the present invention significantly simplify the complexity of the traditional multi-mode generation system and improve the efficiency, stability and flexibility of mode generation. Through innovative optical design and phase control technology, four spatial orthogonal modes, HG10 mode 15, HG01 mode 14, left-handed LG01 mode 16 and right-handed LG01 mode 17, can be efficiently and easily generated simultaneously, compared with the previous need for multiple generation devices and complex steps. The experimental optical path of the device is simple, and only one laser beam is needed to complete the multi-beam generation. Therefore, it is insensitive to the vibration of the surrounding environment and the disturbance of the air, providing strong technical support for the fields of optical communication and optical information processing.

[0041] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0042] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A device for generating four spatial orthogonal patterns simultaneously, characterized in that: These include: Laser source (1): used for outputting a plane wave of a fundamental mode Gaussian beam; Mode converter (2): used to generate standard HG10 mode; Mode shaper (3): used to split and mode shape the standard HG10 mode, and simultaneously output the HG10 mode (15), the HG01 mode (14), the left-handed LG01 mode (16) and the right-handed LG01 mode (17).

2. The device for generating four spatial orthogonal patterns simultaneously according to claim 1, characterized in that: The laser source (1), the mode converter (2) and the mode shaper (3) are arranged on a seismic isolation platform (4).

3. The device for generating four spatial orthogonal patterns simultaneously according to claim 2, characterized in that: The mode converter (2) comprises a phase inversion plate (5) and a mode filter cavity (6); The inversion phase plate (5) is used to convert the fundamental mode Gaussian beam into an approximate HG10 mode; The mode filter cavity (6) is used to filter out stray modes and output a standard HG10 mode.

4. The device for generating four spatial orthogonal patterns simultaneously according to claim 3, characterized in that: The inversion phase plate (5) comprises two glass plates spliced ​​together with different fast axis directions, and has a laser transmittance greater than 98%.

5. The device for generating four spatial orthogonal patterns simultaneously according to claim 3, characterized in that: The mode filtering cavity (6) is a three-mirror annular cavity, including two plane cavity mirrors with a transmittance of 0.3% and a plano-concave mirror with a curvature radius of 1m and a reflectivity greater than 99.9%. The corresponding bandwidth is 600KHz and the cavity fineness is 1000.

6. The device for generating four spatial orthogonal patterns simultaneously according to claim 1, characterized in that: The mode shaper (3) comprises a Dove prism (8), a first reflector (10), a second reflector (11), a first beam splitter (7), a second beam splitter (9), a third beam splitter (12) and a fourth beam splitter (13).

7. The device for generating four spatial orthogonal patterns simultaneously according to claim 6, characterized in that: The transmittance of the dove prism (8) is greater than 98%, and is used to realize the lateral spatial distribution rotation of the light field and convert the HG10 mode into the HG01 mode.

8. The device for generating four spatial orthogonal patterns simultaneously according to claim 6, characterized in that: The reflectivity of the first reflector (10) and the second reflector (11) to laser light is greater than 99.9%, wherein the first reflector (10) is fixedly arranged on the piezoelectric ceramic and is used to lock the relative phase between the HG10 mode and the HG01 mode.

9. The device for generating four spatial orthogonal patterns simultaneously according to claim 8, characterized in that: The first beam splitter (7), the second beam splitter (9), the third beam splitter (12) and the fourth beam splitter (13) are all 50 / 50 beam splitters, used for splitting incident light into two beams of equal light intensity.

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