An adjustable spectrum light source and method of adjusting the same

Abstract

The present application relates to a kind of spectral light source applied to target simulator simulation, specifically relates to a kind of adjustable spectral light source and its adjusting method.Solve the technical problem that the spectral light source obtained from prior art cannot contain multiple spectral information simultaneously, and spectral information is not modulated, so that target simulator is difficult to realistically simulate the scene with spectral information.The adjustable spectral light source of the present application includes exit light source module, spectral decomposition adjustment module and spectral mixing module;Spectral decomposition adjustment module includes filter array, coupling element and spatial light modulator;The exit light of exit light source module is uniformly irradiated to filter array, is divided into different spectral range light after filtering by filter array, then is converged after coupling element, so that the light of each spectral range is located at different positions of spatial light modulator, and after modulation by spatial light modulator, form the divergent light with multiple specific spectral information, and the divergent light is output target spectral light source by spectral mixing module.

Description

Technical Field

[0001] This invention relates to a spectral light source for use in target simulator simulation, specifically to an adjustable spectral light source and its adjustment method. Background Technology

[0002] The principle of a target simulator is to illuminate a spatial light modulator with a light source. The spatial light modulator modulates the incident light, and then the modulated light field is output to the system under test through a projection lens for simulation. The key to a target simulator is to reflect the scene to be simulated as realistically as possible. Therefore, in some special applications, the light source used in a target simulator needs to have certain spectral information.

[0003] In existing technologies, the method for obtaining light sources with spectral information is usually to add different filters or directly add filter wheels to continuous light sources, and finally obtain light sources with different spectral information. The drawback of this method is that the obtained light source cannot contain multiple spectral information at the same time, and the spectral information in the light source cannot be modulated, making it difficult for the target simulator to realistically simulate the scene with spectral information. Summary of the Invention

[0004] The purpose of this invention is to solve the technical problem that the spectral light source obtained by existing technology cannot simultaneously contain multiple spectral information and the spectral information in the final light source cannot be modulated, making it difficult for the target simulator to realistically simulate a scene with spectral information. The invention provides an adjustable spectral light source and its adjustment method.

[0005] The technical solution of this invention is:

[0006] A tunable spectral light source, characterized in that it includes an output light source module, a spectral decomposition and adjustment module, and a spectral mixing module;

[0007] The emitted light source module includes a continuous light source and an illumination element disposed in the emitted light path of the continuous light source; the continuous light source is used to provide broadband raw light;

[0008] The spectral decomposition and adjustment module includes a filter array, a coupling element, and a spatial light modulator, which are sequentially arranged in the light path of the continuous light source and located behind the illumination element.

[0009] The filter array has filters with different center wavelength spectral bands placed at different spatial positions;

[0010] The spectral mixing module includes a first cylindrical mirror and a second cylindrical mirror sequentially disposed on the output optical path of the spatial light modulator, and an integrating sphere disposed on the output optical path of the second cylindrical mirror.

[0011] The first cylindrical mirror is used to shape the surface source light emitted from the spatial light modulator into linear light, and the second cylindrical mirror is used to compress the linear light into a light spot;

[0012] The integrating sphere is provided with an inlet and an outlet, with the inlet located at the incident position of the light spot.

[0013] The emitted beam from the continuous light source is uniformly irradiated onto the filter array after passing through the illumination element. After being filtered by the filter array, the light is divided into different spectral bands. After being converged by the coupling element, the various spectral bands filtered by the filter array are located at different positions of the spatial light modulator. Each spectral band filtered by the filter array is modulated by the spatial light modulator to form divergent light with multiple specific spectral information. The divergent light passes through the first cylindrical mirror and the second cylindrical mirror in sequence to form a light spot that is incident on the integrating sphere. The light spot undergoes multiple diffuse reflections within the integrating sphere and is then output as the required spectral light source at the outlet of the integrating sphere.

[0014] Furthermore, the filter array is a planar strip multi-band filter, a wedge filter, or a filter array composed of multiple single-spectral bands.

[0015] Furthermore, the spatial light modulator is a DMD or LCOS.

[0016] Furthermore, the continuous light source is a point light source or a surface light source, and its spectral range is the visible spectrum, near-infrared spectrum, mid-wave infrared spectrum, or long-wave infrared spectrum.

[0017] Furthermore, the illumination element employs Köhler illumination or Abbe illumination, and the lens adopts a telecentric design to ensure that the light entering the filter array is quasi-parallel light.

[0018] Furthermore, the coupling element is a converging lens of a microlens array; the inner surface of the integrating sphere is coated with a highly reflective material with a reflectivity greater than or equal to 99%.

[0019] Meanwhile, the present invention also provides a method for adjusting the above-mentioned tunable spectral light source, which is characterized by including the following steps:

[0020] 1) Select a continuous light source, filter array, and spatial light modulator that match the spectral range of the target light source, and install and assemble the continuous light source, filter array, and spatial light modulator with the remaining components.

[0021] 2) Turn on the continuous light source, and after passing through the illumination element, the light is evenly shone into the filter array;

[0022] 3) The filter array filters out the incident light to obtain light of different spectral bands, which then enter the spatial light modulator through the coupling element, so that the various spectral bands filtered by the filter array are located at different positions in the spatial light modulator.

[0023] 4) Based on the target spectral light source, the spectral bands and energy of the light incident into the spatial light modulator are simultaneously modulated to form divergent light with multiple specific spectral information, and then the target spectral light source is output through the spectral mixing module.

[0024] The beneficial effects of this invention are:

[0025] 1. This invention provides a tunable spectral light source that combines a filter array and a spatial light modulator. The resulting spectral light source can simultaneously contain multiple spectral information and can output single-spectrum, multi-spectral, or full-spectrum light as needed, with each spectral band being independently tunable. Simultaneously, the spatial light modulator is a two-dimensional array device that can achieve point-to-point modulation and simultaneous modulation of the spectral band and energy of the incident light. The tunable spectral light source provided by this invention employs a filter array, eliminating complex slits and dispersive elements, resulting in a simple overall structure and improved energy utilization. It can output single-spectrum, multi-spectral, or full-spectrum light as needed, with each spectral band being independently tunable.

[0026] 2. The present invention provides an adjustable spectral light source. The light modulated by the spatial light modulator is thoroughly mixed and homogenized by the integrating sphere, forming a new spectral light source at the outlet of the integrating sphere. It can be applied to the field of target simulation or calibration system.

[0027] 3. The present invention provides an adjustable spectral light source with a wide range of applicable spectral bands, applicable to the visible spectrum, near-infrared spectrum, mid-wave infrared spectrum, or long-wave infrared spectrum.

[0028] 4. The present invention provides an adjustable spectral light source, wherein the spatial light modulator is a DMD or LCOS, and a two-dimensional device is used for modulation. On the one hand, the output spectral band can be adjusted, and on the other hand, the energy of the output spectral band can be modulated.

[0029] 5. The present invention provides an adjustable spectral light source, the continuous light source being a point light source or a surface light source, which has a wide range of applications.

[0030] 6. The present invention provides an adjustable spectrum light source, the core component of which adopts a filter array, eliminating the need for slits and greatly improving the energy utilization rate of the system.

[0031] 7. The present invention provides an adjustable spectral light source, wherein all lenses are conventional lenses, the overall structure is simple, the size is small, and it is portable, which can expand the application range of the spectral light source.

[0032] 8. The present invention provides a method for adjusting an adjustable spectral light source. By controlling the energy output of different columns, different spectral bands can be selected. By controlling the number and intensity of modulation units on a certain column, the energy of that spectral band can be modulated, thereby obtaining the desired spectral light source. The method is simple to operate, highly efficient, and the quality of the obtained spectral light source is guaranteed. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the optical path of an embodiment of an adjustable spectral light source according to the present invention;

[0034] Figure 2 This is a schematic diagram of the spectral arrangement of a tunable spectral light source according to an embodiment of the present invention, after passing through a coupling element and entering a spatial light modulator.

[0035] Reference numerals: 1-Continuous light source, 2-Illumination element, 3-Filter array, 4-Coupled element, 5-Spatial light modulator, 6-First cylindrical mirror, 7-Second cylindrical mirror, 8-Integrating sphere. Detailed Implementation

[0036] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0037] This invention provides an adjustable spectral light source, such as... Figure 1 As shown, it includes an output light source module, a spectral decomposition and adjustment module, and a spectral mixing module.

[0038] The output light source module includes a continuous light source 1 and an illumination element 2 disposed on the output light path of the continuous light source. The continuous light source 1 is used to provide broadband raw light. The continuous light source 1 can be a point light source or a surface light source, and its spectral range can be visible light, near-infrared, or infrared, with the infrared range including mid-wave infrared and long-wave infrared. The illumination element 2 uses Köhler illumination or Abbe illumination to uniformly and approximately parallel illuminate the filter array 3. Its lens adopts a telecentric design to ensure that the light entering the filter array 3 is quasi-parallel light.

[0039] The spectral decomposition and adjustment module includes a filter array 3, a coupling element 4, and a spatial light modulator 5, sequentially arranged in the light path of the continuous light source and located behind the illumination element 2. The filter array 3 filters out incident light as it passes through, allowing only the necessary light to pass. Filters with different center wavelength spectral bands are placed at different spatial positions in the filter array 3. After passing through the coupling element 4, the light reaches the spatial light modulator 5, ensuring that the various spectral bands filtered by the filter array 3 are located at different positions within the spatial light modulator 5. The filter array 3 can be a planar strip multi-band filter, a wedge-shaped filter, or a filter array composed of multiple single-spectral bands. The spatial light modulator 5 is a two-dimensional array, with one dimension being the spectral dimension and the other the intensity dimension. By modulating the energy transmitted through each pixel in the intensity dimension, the energy of the spectrum in that column is controlled, thus achieving spectral adjustability. Each pixel of the spatial light modulator 5 can be controlled individually. The arrangement of light entering the spatial light modulator 5 after passing through the coupling element 4 is shown in the attached figure. Figure 2As shown, different filling patterns represent different spectra at different positions on the spatial light modulator 5. One dimension represents the direction of light in different spectral bands, each column represents a different spectral band, and the other dimension modulates the light energy in that column, thus achieving simultaneous modulation of the spectral band and energy of the incident light. The modulation principle of the spatial light modulator 5 is as follows: by modulating the energy of different columns, different spectral bands of light output can be selected. By controlling the number and intensity of modulation units in a certain column, the energy of that column's spectral band can be modulated. The spatial light modulator 5 is generally a DMD or LCOS. The coupling element 4 uses a converging lens of a microlens array, which can collect energy more efficiently.

[0040] The spectral mixing module includes a first cylindrical mirror 6 and a second cylindrical mirror 7 sequentially arranged in the output light path of the spatial light modulator 5, and an integrating sphere 8 arranged in the output light path of the second cylindrical mirror 7. The integrating sphere 8 has an inlet and an outlet, with the inlet located at the incident position of the light spot. The inner surface of the integrating sphere is coated with a highly reflective material with a reflectivity greater than or equal to 99%. The energy modulated by the spatial light modulator 5 is divergent light at different angles, which passes sequentially through two cylindrical mirrors in different directions. The first cylindrical mirror 6 and the second cylindrical mirror 7 are arranged consecutively, and the cylindrical mirrors can shape the surface source light into linear light. The first cylindrical mirror 6 is used to shape the surface source light emitted from the spatial light modulator 5 into linear light, and the second cylindrical mirror 7 is used to compress the linear light to form a small light spot.

[0041] The optical principle of this invention is as follows: A continuous light source 1 provides a broadband original light beam. After passing through the illumination element 2, the emitted light beam is uniformly irradiated onto the filter array 3. After being filtered by the filter array 3, the light is converted into light of different spectral bands. Then, it passes through the coupling element 4, so that the various spectral bands filtered by the filter array 3 are distributed at different positions of the spatial light modulator 5. After being modulated by the spatial light modulator 5, it forms a divergent light with multiple specific spectral information. The divergent light passes sequentially through the first cylindrical mirror 6 and the second cylindrical mirror 7. The first cylindrical mirror 6 first shapes the incident divergent light into linear light. The second cylindrical mirror 7 is placed perpendicular to the first cylindrical mirror 6 and compresses the linear light to form a small light spot. This light spot is incident at the entrance of the integrating sphere and is input into the integrating sphere as a new divergent light source. The light emitted by the new divergent light source undergoes multiple diffuse reflections in the integrating sphere, so that the light of different spectral bands is fully mixed before being output, forming a spectral light source with uniform spectral characteristics for use by subsequent systems.

[0042] Meanwhile, the present invention also provides a method for adjusting the above-mentioned tunable spectral light source, comprising the following steps:

[0043] 1) Select a continuous light source 1, filter array 3, and spatial light modulator 5 that match the spectral range of the target light source to be obtained, and install and build the continuous light source 1, filter array 3, spatial light modulator 5, and other components.

[0044] 2) Turn on the continuous light source 1, and after passing through the illumination element 2, the light is evenly shone into the filter array 3;

[0045] 3) The filter array 3 filters out the incident light to obtain light of different spectral bands, which then enter the spatial light modulator 5 through the coupling element 4, so that the various spectral bands filtered by the filter array 3 are located at different positions in the spatial light modulator 5.

[0046] 4) Based on the target spectral light source, the spectral band and energy of the light incident into the spatial light modulator 5 are simultaneously modulated to form divergent light with multiple specific spectral information, and then output through the spectral mixing module to obtain the target spectral light source.

[0047] This invention discloses an adjustable spectral light source, which achieves its adjustable function mainly through a filter array 3 and a spatial light modulator 5. The spatial light modulator 5 can output monospectral, multispectral, or hyperspectral light, and can also modulate the energy of the spectrum to obtain the desired target spectral light source.

Claims

1. An adjustable spectral light source, characterized by: It includes an output light source module, a spectral decomposition and adjustment module, and a spectral mixing module; The emitted light source module includes a continuous light source (1) and an illumination element (2) disposed in the emitted light path of the continuous light source; the continuous light source (1) is used to provide broadband raw light; The spectral decomposition and adjustment module includes a filter array (3), a coupling element (4), and a spatial light modulator (5) arranged sequentially on the light path of the continuous light source and located behind the illumination element (2); The filter array (3) has filters with different center wavelength spectral bands placed at different spatial positions; The spectral mixing module includes a first cylindrical mirror (6) and a second cylindrical mirror (7) sequentially disposed on the output optical path of the spatial light modulator (5), and an integrating sphere (8) disposed on the output optical path of the second cylindrical mirror (7); The first cylindrical mirror (6) is used to shape the surface source light emitted from the spatial light modulator (5) into linear light, and the second cylindrical mirror (7) is used to compress the linear light into a light spot; The integrating sphere (8) is provided with an inlet and an outlet, with the inlet located at the incident position of the light spot; The emitted beam from the continuous light source (1) is uniformly irradiated onto the filter array (3) after passing through the illumination element (2). After being filtered by the filter array (3), the light is divided into different spectral bands. After being converged by the coupling element (4), the various spectral bands filtered by the filter array (3) are located at different positions of the spatial light modulator (5). After being modulated by the spatial light modulator (5), the various spectral bands filtered by the filter array (3) form divergent light with multiple specific spectral information. The divergent light passes through the first cylindrical mirror (6) and the second cylindrical mirror (7) in sequence to form a light spot that is incident into the integrating sphere (8). The light spot undergoes multiple diffuse reflections in the integrating sphere (8) and then outputs the required spectral light source at the outlet of the integrating sphere (8).

2. The tunable spectral light source according to claim 1, characterized in that: The filter array (3) is a planar strip multi-band filter, a wedge filter, or a filter array composed of multiple single-spectral bands.

3. A tunable spectral light source according to claim 1 or 2, characterized in that: The spatial light modulator (5) is a DMD or LCOS.

4. The tunable spectral light source according to claim 3, characterized in that: The continuous light source (1) is a point light source or a surface light source, and its spectral range is the visible spectrum, near-infrared spectrum, mid-wave infrared spectrum or long-wave infrared spectrum.

5. The tunable spectral light source according to claim 4, characterized in that: The illumination element (2) uses Köhler illumination or Abbe illumination, and the lens adopts a telecentric design to ensure that the light entering the filter array (3) is quasi-parallel light.

6. The tunable spectral light source according to claim 5, characterized in that: The coupling element (4) is a converging lens of a microlens array; The inner surface of the integrating sphere (8) is coated with a highly reflective material with a reflectivity greater than or equal to 99%.

7. A method of adjusting a tunable spectral light source as claimed in any one of claims 1 to 6, characterized in that Includes the following steps: 1) Select a continuous light source (1), filter array (3), and spatial light modulator (5) that match the spectral range of the target light source, and install the continuous light source (1), filter array (3), and spatial light modulator (5) with the other components. 2) Turn on the continuous light source (1), and after passing through the lighting element (2), the light is evenly shone into the filter array (3); 3) The filter array (3) filters out the incident light to obtain light of different spectral bands, and then enters the spatial light modulator (5) through the coupling element (4), so that each spectral band after being filtered by the filter array (3) is located at a different position in the spatial light modulator (5). 4) Based on the target spectral light source, the spectral band and energy of each spectral band of the light incident into the spatial light modulator (5) are simultaneously modulated to form divergent light with multiple specific spectral information, and then the target spectral light source is output through the spectral mixing module.

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