Acousto-optic modulator and acousto-optic device
By introducing a polarizer and a bandpass filter into the acousto-optic modulator, the light beam is converted into polarization-maintaining light, which solves the problem of high light source requirements in the existing technology and achieves wide application and cost reduction.
Patent Information
- Application Number
- CN202423070575.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-12
- Publication Date
- 2025-10-03
- Estimated Expiration
- 2034-12-12
AI Technical Summary
Existing fiber-coupled acousto-optic modulators have high requirements for light sources, resulting in a small application range and an inability to effectively utilize non-polarization-maintaining light sources.
A polarizer is introduced into the acousto-optic modulator to convert the light beam into polarization-maintaining light, and a bandpass filter is combined to narrow the beam bandwidth to achieve effective modulation of the non-polarization-maintaining light source.
The application range of the acousto-optic modulator is expanded, the cost of the light source is reduced, and polarization-maintaining modulated light can be obtained using a non-polarization-maintaining light source.
Smart Images
Figure CN223413570U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of acousto-optic modulation technology, and in particular to an acousto-optic modulator and an acousto-optic device. Background Art
[0002] A fiber-coupled acousto-optic modulator (AOM) operates based on the principle of acousto-optic interaction and has broad applications in fiber-optic communications, fiber-optic sensing, and optical signal processing. A driver outputs an RF signal, which is applied to a piezoelectric transducer via a matching circuit. This RF signal excites ultrasonic waves of the same frequency into the acousto-optic medium. These waves periodically modulate the optical refractive index of the acousto-optic medium, forming an equivalent phase grating. Continuous input light enters the acousto-optic crystal through an input collimator, where it diffracts the refractive index grating to produce diffracted light. This diffracted light is then transmitted to the end of the optical fiber through an output collimator, where it is then reconstructed as diffracted light.
[0003] Existing fiber-coupled acousto-optic modulators (AOMs) are all longitudinal wave devices. Due to the properties of acousto-optic crystals and the principles of acousto-optics, longitudinal wave devices have the property that the polarization direction of the diffracted light is the same as the incident light. In other words, if the incident light is vertical, the diffracted light is also vertical; if the incident light is non-polarization-maintaining, the diffracted light is also non-polarization-maintaining. If the user's light source is non-polarization-maintaining but polarization-maintaining light is required, this can only be achieved by replacing the light source. Therefore, existing fiber-coupled AOMs have high light source requirements and a limited range of applications. Utility Model Content
[0004] The purpose of this application is to address the deficiencies in the above-mentioned prior art and provide an acousto-optic modulator and an acousto-optic device, which have a wide range of applications and can reduce the cost of light sources.
[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of the present application are as follows:
[0006] In one aspect of an embodiment of the present application, an acousto-optic modulator is provided, comprising: a housing, an acousto-optic modulation module and a polarizer disposed within the housing, and a beam input member and a beam output member disposed on the housing, wherein the beam input member, the polarizer, the acousto-optic modulation module, and the beam output member are sequentially distributed along a transmission path of the light beam, the beam input member and the beam output member are used to transmit the light beam, the polarizer is used to convert the light beam into polarization-maintaining light, and the acousto-optic modulation module is used to modulate the light beam.
[0007] Optionally, a bandpass filter is further included, which is arranged on the transmission path of the light beam. The bandpass filter is located between the light beam input component and the light beam output component, and is used to narrow the bandwidth of the light beam.
[0008] Optionally, the polarizer is rotatably disposed within the housing.
[0009] Optionally, the polarizer is a polarization beam splitter prism.
[0010] Optionally, a bandpass filter is located between the acousto-optic modulation module and the light beam output element.
[0011] Optionally, the bandpass filter is a narrowband filter.
[0012] Optionally, the acousto-optic modulation module includes a matching circuit board, an acousto-optic crystal, and a piezoelectric transducer and a radio frequency connector electrically connected to the matching circuit board, respectively. The acousto-optic crystal is located on the transmission path of the light beam, the piezoelectric transducer is located on the surface of the acousto-optic crystal, and the radio frequency connector is exposed on the outer casing.
[0013] Optionally, the acousto-optic crystal is a longitudinal wave crystal or a slow shear wave crystal.
[0014] Optionally, both the beam input element and the beam output element are beam collimators.
[0015] In another aspect of an embodiment of the present application, an acousto-optic device is provided, comprising a light source and an acousto-optic modulator as described above, wherein the light source is configured to emit a light beam toward the acousto-optic modulator, and the acousto-optic modulator is located on a transmission path of the light beam.
[0016] The beneficial effects of this application include:
[0017] The present application provides an acousto-optic modulator, comprising: a housing, an acousto-optic modulation module and a polarizer disposed within the housing, and a beam input and a beam output disposed on the housing. The beam input, polarizer, acousto-optic modulation module, and beam output are sequentially arranged along the transmission path of the light beam. The beam input and beam output are used to transmit the light beam, the polarizer is used to convert the light beam into polarization-maintaining light, and the acousto-optic modulation module is used to modulate the light beam. The acousto-optic modulator has a polarizer disposed between the beam input and the acousto-optic modulation module. The polarizer is used to convert the light beam emitted by the light source into polarization-maintaining light, so that the resulting modulated light is polarization-maintaining light. Therefore, the acousto-optic modulator can obtain polarization-maintaining modulated light even using a non-polarization-maintaining light source, has a wide range of applications, and can reduce the cost of the light source. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.
[0019] Figure 1 A schematic diagram of the structure of the acousto-optic modulator provided in an embodiment of the present application;
[0020] Figure 2This is a light path diagram of the acousto-optic modulator provided in an embodiment of the present application.
[0021] Icons: 100-Acousto-optic modulator; 110-Housing; 120-Acousto-optic modulation module; 121-Matching circuit board; 122-Acousto-optic crystal; 123-RF connector; 124-Piezoelectric transducer; 130-Polarizer; 140-Beam input; 150-Beam output; 160-Bandpass filter; 210-Beam; 220-Polarization-maintaining light; 230-Polarization-maintaining narrowband light. DETAILED DESCRIPTION
[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.
[0023] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application as claimed, but merely represents selected embodiments of the present application. It should be noted that, unless there is a conflict, the various features of the embodiments of the present application may be combined with each other, and the combined embodiments are still within the scope of protection of the present application.
[0024] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition or explanation in subsequent drawings.
[0025] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of this application is typically placed when in use. These terms are intended only to facilitate the description of this application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0026] Furthermore, terms such as "horizontal" and "vertical" do not necessarily mean that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.
[0027] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.
[0028] In one aspect of the embodiment of this application, please refer to Figure 1 and Figure 2 An acousto-optic modulator 100 is provided, comprising: a housing 110, an acousto-optic modulation module 120 and a polarizer 130 disposed within the housing 110, and a beam input member 140 and a beam output member 150 disposed on the housing 110. The beam input member 140, the polarizer 130, the acousto-optic modulation module 120, and the beam output member 150 are sequentially distributed along a transmission path of a light beam 210. The beam input member 140 and the beam output member 150 are used to transmit the light beam 210, the polarizer 130 is used to convert the light beam 210 into polarization-maintaining light 220, and the acousto-optic modulation module 120 is used to modulate the light beam 210.
[0029] The housing 110 supports and protects the internal components of the AOM 100, protecting them from external pressure, impact, and dust, ensuring their proper operation and extending their service life. The internal components of the AOM 100 include at least a beam input 140, an AOM module 120, a polarizer 130, and a beam output 150. The AOM 100 must be used in conjunction with a light source capable of emitting a light beam 210. The beam input 140, AOM module 120, polarizer 130, and beam output 150 of the AOM 100 are spaced apart in sequence along the transmission path of the light beam 210, away from the light source.
[0030] The beam input member 140 is closest to the light source. A light beam 210 emitted by the light source enters the housing 110 through the beam input member 140, is transmitted through the beam input member 140, and is emitted toward the polarizer 130. The polarizer 130 converts the light beam 210 into polarization-maintaining light 220. After leaving the polarizer 130, the polarization-maintaining light 220 is emitted toward the acousto-optic modulation module 120. The acousto-optic modulation module 120 modulates the polarization-maintaining light 220. The modulated polarization-maintaining light 220 is emitted toward the beam output member 150, is transmitted through the beam output member 150, and then exits the acousto-optic modulation module 100.
[0031] The AOM 100 includes a polarizer 130 disposed between the light beam input element 140 and the AOM module 120. The polarizer 130 converts the light beam 210 emitted by the light source into polarization-maintaining light 220, thereby obtaining polarization-maintaining modulated light 220. Therefore, the AOM 100 can generate polarization-maintaining modulated light even when using a non-polarization-maintaining light source, thus broadening its application range and reducing light source costs.
[0032] Optionally, the polarizer 130 is rotatably disposed in the housing 110. In this way, vertical polarization-maintaining light 220 or horizontal polarization-maintaining light 220 can be obtained by rotating the polarizer 130, thereby further expanding the application range of the AOM 100.
[0033] It should be noted that, in this embodiment, the structure for driving the polarizer 130 to rotate is not limited, as long as it can drive the polarizer 130 to rotate.
[0034] In other embodiments, the polarizer 130 may also be fixed in the housing 110. When the polarization direction of the modulated light needs to be changed, the placement angle of the polarizer 130 is manually adjusted and the polarizer 130 is fixed, thereby outputting polarization-maintaining light 220 with different polarization directions.
[0035] Optionally, the polarizer 130 is a polarization beam splitter prism.
[0036] The polarization beam splitter is capable of separating the horizontally polarized and vertically polarized light beam 210. When light beam 210 is incident at the Brewster angle, the transmittance of P-polarized light (polarized light parallel to the plane of incidence) is 1, while the transmittance of S-polarized light (polarized light perpendicular to the plane of incidence) is less than 1. The multilayer film structure in the polarization beam splitter enables complete separation of P-polarized light and S-polarized light, ensuring a P-light transmittance of over 90%.
[0037] Polarization beam splitters offer numerous advantages, including high extinction ratio, low stress, strong polarization-maintaining capability, and a small beam deflection angle. Their application in the AOM 100 ensures excellent polarization-maintaining performance and helps maintain a stable and precise optical path. During operation, the AOM 100 can output polarization-maintaining light 220 with varying polarization directions by adjusting the angle of the polarization beam splitter.
[0038] Optionally, the AOM 100 further includes a bandpass filter 160 disposed on the transmission path of the light beam 210 . The bandpass filter 160 is located between the light beam input element 140 and the light beam output element 150 . The bandpass filter 160 is used to narrow the bandwidth of the light beam 210 .
[0039] Bandpass filter 160 allows light beam 210 within a specific wavelength range to pass through while suppressing light beams 210 of other wavelengths. Placing bandpass filter 160 along the transmission path of light beam 210 can filter out light beam 210 outside the specific wavelength range, thereby narrowing the bandwidth of light beam 210 and producing polarization-maintaining narrowband light 230. The combination of polarizer 130 and bandpass filter 160 enables the acousto-optic modulator 100 to produce polarization-maintaining narrowband modulated light even when using a non-polarization-maintaining broadband light source, further reducing costs and expanding its application range.
[0040] Optionally, the bandpass filter 160 is a narrowband filter.
[0041] Narrowband filters have advantages such as high transmittance, narrow bandwidth, good cutoff characteristics, stability, and high selectivity. Using narrowband filters to filter light beam 210 enables precise screening of light beam 210 and improves the performance of AOM 100. Narrowband filters can use filters with bandwidths of 2 nm to 10 nm or other bandwidths.
[0042] Optionally, the bandpass filter 160 is located between the AOM module 120 and the light beam output element 150 .
[0043] The polarizer 130 is disposed between the beam input component 140 and the acousto-optic modulation module 120 . In this case, the bandpass filter 160 is disposed between the acousto-optic modulation module 120 and the beam output component 150 , which can make the layout of the components in the housing 110 more reasonable.
[0044] Optionally, the acousto-optic modulation module 120 includes a matching circuit board 121, an acousto-optic crystal 122, and a piezoelectric transducer 124 and a radio frequency connector 123 electrically connected to the matching circuit board 121, respectively. The acousto-optic crystal 122 is located on the transmission path of the light beam 210, the piezoelectric transducer 124 is located on the surface of the acousto-optic crystal 122, and the radio frequency connector 123 is exposed on the housing 110.
[0045] External electrical signals are sequentially loaded onto the piezoelectric transducer 124 via the RF connector 123 and the matching circuit board 121. The piezoelectric transducer 124 utilizes the inverse piezoelectric effect of the piezoelectric material to convert the electrical signals into mechanical vibrations, thereby generating ultrasonic waves. When ultrasonic waves propagate through the acousto-optic crystal 122, elastic stress is generated within the acousto-optic crystal 122, causing the refractive index of the acousto-optic crystal 122 to undergo periodic changes, forming a grating structure. When polarization-maintaining light 220 passes through the periodically changing acousto-optic crystal 122, light diffraction occurs. The intensity, frequency, and direction of the diffracted light vary with the wavefield, thereby modulating the light beam 210.
[0046] Optionally, the acousto-optic crystal 122 is a longitudinal wave crystal or a slow shear wave crystal.
[0047] After a certain polarization-maintaining light 220 enters the longitudinal wave crystal or the slow-shear wave crystal and undergoes acousto-optic interaction, it is still output in the form of polarization-maintaining light 220 .
[0048] Optionally, both the beam input element 140 and the beam output element 150 are beam collimators.
[0049] The beam collimator can adjust the light beam 210 into parallel light, thereby improving the light coupling efficiency and transmission quality.
[0050] This embodiment further provides an acousto-optic device, comprising a light source and an acousto-optic modulator 100 as described above. The light source is configured to emit a light beam 210 toward the acousto-optic modulator 100 , and the acousto-optic modulator 100 is located on a transmission path of the light beam 210 .
[0051] The acousto-optic device has the same structure and benefits as the acousto-optic modulator 100 in the aforementioned embodiment. The structure and benefits of the acousto-optic modulator 100 have been described in detail in the aforementioned embodiment and will not be repeated here.
[0052] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.
Claims
1. An acousto-optic modulator, characterized in that: include: A housing, an acousto-optic modulation module and a polarizer arranged in the housing, and a beam input member and a beam output member arranged on the housing, wherein the beam input member, the polarizer, the acousto-optic modulation module and the beam output member are sequentially distributed along a transmission path of the light beam, the beam input member and the beam output member are used to transmit the light beam, the polarizer is used to convert the light beam into polarization-maintaining light, and the acousto-optic modulation module is used to modulate the light beam.
2. The acousto-optic modulator according to claim 1, wherein It also includes a bandpass filter arranged on the transmission path of the light beam, the bandpass filter is located between the light beam input component and the light beam output component, and the bandpass filter is used to narrow the bandwidth of the light beam.
3. The acousto-optic modulator according to claim 1, wherein The polarizer is rotatably disposed in the housing.
4. The acousto-optic modulator according to claim 1, wherein The polarizer is a polarization beam splitter prism.
5. The acousto-optic modulator according to claim 2, wherein The bandpass filter is located between the acousto-optic modulation module and the light beam output element.
6. The acousto-optic modulator according to claim 2, wherein The bandpass filter is a narrowband filter.
7. The acousto-optic modulator according to any one of claims 1 to 6, wherein: The acousto-optic modulation module includes a matching circuit board, an acousto-optic crystal, and a piezoelectric transducer and a radio frequency connector electrically connected to the matching circuit board, respectively. The acousto-optic crystal is located on the transmission path of the light beam, the piezoelectric transducer is located on the surface of the acousto-optic crystal, and the radio frequency connector is exposed from the housing.
8. The acousto-optic modulator according to claim 7, wherein The acousto-optic crystal is a longitudinal wave crystal or a slow shear wave crystal.
9. The acousto-optic modulator according to any one of claims 1 to 6, wherein: The beam input component and the beam output component are both beam collimators.
10. An acousto-optic device, characterized in that The device comprises a light source and an acousto-optic modulator according to any one of claims 1 to 9, wherein the light source is used to emit a light beam to the acousto-optic modulator, and the acousto-optic modulator is located on a transmission path of the light beam.