Monochromator based on liquid crystal polarization grating

Abstract

The utility model discloses a monochromator based on a liquid crystal polarization grating, which comprises a polarization grating diffraction module, a strip-shaped electrode liquid crystal optical switch module, a polarization grating collimation module, a polarization grating convergence module and an optical fiber coupling module, the strip-shaped electrode liquid crystal optical switch module is used for filtering, the polarization grating collimation module is used for collimation, the polarization grating convergence module is used for convergence, and finally, the strip-shaped electrode liquid crystal optical switch module is used for coupling and outputting through the optical fiber coupling module, and comprises a power supply circuit, a driving circuit, strip-shaped electrodes and a liquid crystal layer located between the strip-shaped electrodes; the light transmission of a liquid crystal layer in the strip-shaped electrode liquid crystal optical switch module is changed by applying voltage or current, and on-off control of optical signals is achieved. According to the utility model, the monochromatic light separation efficiency, purity and light path control flexibility are obviously improved, light loss and noise interference are reduced, and the overall performance and stability of the system are improved.

Description

Technical Field

[0001] The utility model relates to a monochromator, and in particular to a high-performance and highly flexible monochromator based on a liquid crystal polarization grating. Background Art

[0002] In the field of optics, as an optical instrument capable of accurately separating and outputting light of a single wavelength, a monochromator is widely used in multiple fields such as spectral analysis, optical measurement, and laser technology. Traditional monochromators usually use prisms or gratings as dispersive elements, and select different wavelengths by rotating or moving the dispersive elements. However, these methods have certain limitations in terms of accuracy, stability, and efficiency; monochromators based on polarization gratings have received increasing attention due to their unique polarization selectivity and high-efficiency optical performance. How to design a high-performance and highly flexible polarization grating monochromator is an urgent problem to be solved. Summary of the Utility Model

[0003] Purpose of the utility model: The purpose of the utility model is to provide a high-performance and highly flexible monochromator based on a liquid crystal polarization grating.

[0004] Technical solution: The device of the utility model includes a polarization grating diffraction module, a strip electrode liquid crystal light switch module, a polarization grating collimation module, a polarization grating focusing module, and an optical fiber coupling module. The light emitted by the light source is successively diffracted and separated by the polarization grating diffraction module, filtered by the strip electrode liquid crystal light switch module, collimated by the polarization grating collimation module, focused by the polarization grating focusing module, and finally coupled and output through the optical fiber coupling module. The strip electrode liquid crystal light switch module includes a power supply circuit, a drive circuit, strip electrodes, and a liquid crystal layer located between the strip electrodes. By applying a voltage or current, the light transmissivity of the liquid crystal layer in the strip electrode liquid crystal light switch module is changed to achieve the on-off control of the optical signal.

[0005] Further, the strip electrodes change the light transmissivity of the liquid crystal by applying a voltage or current.

[0006] Further, the light transmissivity of the liquid crystal layer changes with the voltage or current applied to the electrodes.

[0007] Further, at a specific voltage or current, the liquid crystal molecules in the liquid crystal layer are arranged in an orderly manner, allowing light to pass through; at other voltages or currents, the liquid crystal molecules are arranged disorderly, blocking the light from passing through.

[0008] Further, the liquid crystal layer uses cyanobiphenyl liquid crystal.

[0009] Further, the power supply circuit includes a voltage conversion, filtering, and voltage stabilization circuit.

[0010] Further, the drive circuit includes a logic circuit and a power amplifier.

[0011] Beneficial effects: Compared with the prior art, the present utility model has the following advantages: the present utility model significantly improves the monochromatic light separation efficiency, purity and optical path control flexibility, meeting the requirements of high-precision and rapidly changing optical experiments; optimizes the quality of the output beam, providing better conditions for subsequent optical processing and fiber coupling; improves the fiber coupling efficiency, reduces light loss and noise interference, and enhances the overall performance and stability of the system. Description of the Drawings

[0012] Figure 1 is a schematic structural diagram of the present utility model;

[0013] Figure 2 is a schematic structural diagram of the strip electrode liquid crystal light switch module. Detailed Embodiments

[0014] The technical solution of the present utility model will be further described below with reference to the drawings.

[0015] As Figure 1 shown, the device of the present utility model includes a polarization grating diffraction module 1, a strip electrode liquid crystal light switch module 2, a polarization grating collimation module 3, a polarization grating focusing module 4, and a fiber coupling module 5. The light emitted by the light source is successively diffracted and separated by the polarization grating diffraction module 1, filtered by the strip electrode liquid crystal light switch module 2, collimated by the polarization grating collimation module 3, focused by the polarization grating focusing module 4, and finally coupled and output through the fiber coupling module 5. By applying a voltage or current, the light transmissivity of the liquid crystal layer in the strip electrode liquid crystal light switch module 2 is changed to realize the on-off control of the optical signal.

[0016] Polarization grating diffraction module 1: includes a polarization grating to realize the diffraction and separation of light.

[0017] Strip electrode liquid crystal light switch module 2: includes a strip electrode and a liquid crystal layer, and controls the on-off of the optical path through an electrical signal.

[0018] Polarization grating collimation module 3: the second polarization grating, used for beam collimation.

[0019] Polarization grating focusing module 4: the third polarization grating or a focusing lens, used for beam focusing.

[0020] Fiber coupling module 5: includes an optical fiber and a coupling device to realize the efficient transmission of the optical signal to the optical fiber.

[0021] As Figure 2 shown, the strip electrode liquid crystal light switch module 2 includes a power supply circuit, a drive circuit, a strip electrode, and a liquid crystal layer located between the strip electrodes.

[0022] Power supply circuit: It provides a stable DC power supply for the entire optical switch system, usually including circuits such as voltage conversion, filtering, and voltage regulation.

[0023] Driver circuit: It is responsible for converting the control signal into a signal suitable for driving the strip electrodes, usually including logic circuits, power amplifiers, etc.

[0024] Strip electrode: As the control end of the optical switch, it changes the light transmittance of the liquid crystal by applying voltage or current.

[0025] Liquid crystal layer: It is located between the strip electrodes and is the core part of the optical switch. Its light transmittance changes with the voltage or current applied to the electrodes.

[0026] When an external control signal is applied to the strip electrodes through the driver circuit, an electric field will be generated between the electrodes. The action of the electric field will change the arrangement of liquid crystal molecules, thereby affecting the light transmittance of the liquid crystal layer. At a specific voltage or current, the liquid crystal molecules will be arranged orderly to allow light to pass through; while at other voltages or currents, the liquid crystal molecules will be arranged disorderly to block light from passing through. By controlling the voltage or current applied to the strip electrodes, the light transmittance state of the liquid crystal optical switch can be switched, thereby realizing the on-off control of the optical signal.

[0027] Liquid crystal material: A liquid crystal material with high birefringence and good optoelectronic properties is selected, such as cyanobiphenyl liquid crystals, to ensure the diffraction efficiency and stability of the grating. Grating period and thickness: According to the target wavelength range and diffraction efficiency requirements, the period and thickness of the grating are precisely designed. The period determines the wavelength interval of the diffracted light, while the thickness affects the diffraction efficiency and the optical path length. By controlling the alignment direction of liquid crystal molecules with an external electric field, the polarization characteristics of the grating are changed, realizing the selective diffraction of light with different wavelengths.

[0028] Working principle:

[0029] When parallel light is incident on the liquid crystal polarization grating, due to the birefringence effect of liquid crystal molecules on light, light with different wavelengths will be diffracted at different angles. By adjusting the intensity and direction of the external electric field, the arrangement of liquid crystal molecules can be precisely controlled, and then the enhancement or suppression of light with a specific wavelength can be realized.

Claims

1. A monochromator based on a liquid crystal polarization grating, characterized in that: It includes a polarization grating diffraction module (1), a strip electrode liquid crystal optical switch module (2), a polarization grating collimation module (3), a polarization grating focusing module (4) and an optical fiber coupling module (5). The light emitted by the light source is successively diffraction-separated by the polarization grating diffraction module (1), filtered by the strip electrode liquid crystal optical switch module (2), collimated by the polarization grating collimation module (3), focused by the polarization grating focusing module (4), and finally coupled and output through the optical fiber coupling module (5). The strip electrode liquid crystal optical switch module (2) includes a power supply circuit, a driving circuit, strip electrodes and a liquid crystal layer located between the strip electrodes. By applying a voltage or current, the light transmissivity of the liquid crystal layer in the strip electrode liquid crystal optical switch module (2) is changed to realize the on-off control of the optical signal.

2. The monochromator based on a liquid crystal polarization grating according to claim 1, wherein: The strip electrodes change the light transmissivity of the liquid crystal by applying a voltage or current.

3. The monochromator based on a liquid crystal polarization grating according to claim 1, wherein: The light transmissivity of the liquid crystal layer changes with the voltage or current applied to the electrodes.

4. The monochromator based on a liquid crystal polarization grating according to claim 1, wherein: At a specific voltage or current, the liquid crystal molecules in the liquid crystal layer will be arranged orderly to allow light to pass through; at other voltages or currents, the liquid crystal molecules will be arranged disorderly to block light from passing through.

5. The monochromator based on a liquid crystal polarization grating according to claim 1, characterized in that: The liquid crystal layer uses cyano-biphenyl liquid crystal.

6. The monochromator based on a liquid crystal polarization grating according to claim 1, wherein: The power supply circuit includes a voltage conversion, filtering and voltage stabilization circuit.

7. The monochromator based on a liquid crystal polarization grating according to claim 1, wherein: The driving circuit includes a logic circuit and a power amplifier.

Images