CN116338970A - A method for obtaining high-power, high-uniformity, high-collimation, ultra-narrow-band line light source - Google Patents

Abstract

The invention discloses a method for obtaining a high-power, high-uniformity, high-collimation and ultra-narrow band line light source, which comprises the following steps: the system light source outputs a parallel laser beam; the light beam is incident to the Bawil prism to realize expansion in the vertical direction; the expanded light beam is incident to a cylindrical mirror, and the expanded light beam is collimated, so that an output light beam is parallel light; the output long-strip parallel light is emitted to another long Jiao Zhumian mirror, and the long-strip parallel light is converged; the converging light beam is emitted to a short-focus cylindrical mirror, and the emergent light beam is corrected to be a parallel light beam, so that a high-power, high-uniformity, high-collimation and ultra-narrow-band linear light source is obtained; the detectors are placed at different locations to see the quality and illumination of the outgoing beam at different locations in the system. The invention utilizes reasonable combination of the Bawil prism and the aspheric plano-convex cylindrical lens with different focal lengths to obtain a beam of high-power, high-uniformity, high-collimation and ultra-narrow-band linear light source, and can be applied to detection of high-precision optical elements and chips.

Description

A method for obtaining high power, high uniformity, high collimation, and ultra-narrowband line light source

technical field

The invention relates to a method for obtaining a high-power, high-uniformity, high-collimation, and ultra-narrow-band line light source, and belongs to the technical field of optical high-precision detection and illumination.

Background technique

For the inspection of high-precision optical components and chips, the traditional method is the visual method, which detects with the naked eye and a microscope, and judges the pros and cons of the detection target and defects based on past experience. This method is simple to operate and does not require high equipment. However, there are shortcomings such as low detection efficiency, strong subjectivity, lack of unified standards, low detection accuracy, and slow detection speed. In order to overcome the above defects, a high-performance line light source can be used to scan the detection element, and a line-scan industrial camera can be used for shooting, which can realize high-speed, large-format and high-precision detection. The higher the detection accuracy of the system, the higher the requirements for the beam quality of the line light source.

At present, most of the existing line light sources use LED light sources as the basic light source, which are formed by linear arrangement, and then collimated by collimating lenses. However, because the light emitted by the LED light source is chaotic, the divergence angle of the beam after passing through the collimating lens is still very large, and the energy distribution of the beam is uneven, and the width of the light source is relatively large. If the target distance of the application scene is far away, the beam is very divergent, and the beam energy cannot meet the application requirements. For scenes that require high-precision display and detection, the uneven brightness of the light source to the target will not meet the high-precision requirements of the system.

To sum up, although the current line light source has been widely used in various fields, the beam quality is also improving. However, there are still disadvantages such as large beam divergence, uneven spot distribution, wide beam line, and weak energy. In addition, traditional detection methods have disadvantages such as low detection efficiency, strong subjectivity, lack of uniform standards, low detection accuracy, and slow detection speed.

Contents of the invention

The present invention aims to solve the problems of the existing line light sources such as large beam divergence, uneven distribution of light spots, wide beam line, and weak energy, and proposes a high-power, high-uniformity, high-collimation, ultra-narrow-band line light source Methods.

The present invention can be realized through the following technical solutions:

A method for obtaining high-power, high-uniformity, high-collimation, ultra-narrow-band line light source, comprising the following steps:

Step 1, the system light source outputs a parallel laser beam;

Step 2, the light beam is incident on the Powell prism to expand in the vertical direction;

Step 3, the expanded beam is incident on the cylindrical mirror, and the expanded beam is collimated so that the output beam is parallel light;

Step 4, the outputted strips of parallel light are emitted to another telephoto cylindrical lens to converge the strips of parallel light;

Step 5, the converging light beam is emitted to the short-focus cylindrical mirror, and the outgoing light beam is corrected into a parallel light beam, thereby obtaining a high-power, high-uniformity, high-collimation, and ultra-narrow-band line light source;

Step six, place detectors at different positions to check the quality and illuminance of the outgoing beam at different positions of the system.

Further, the light source in the first step is a high-performance white laser light source, the spot diameter is 2 mm, and the output beam is approximately parallel light.

Further, the Powell prism described in step 2 has a roof shape with a roof angle of 60°, the prism material is N-SF6, the refractive index is 1.805, and the Abbe number is 25.36.

Further, the cylindrical lens described in step 3 and step 4 is a high-order aspheric plano-convex cylindrical lens with a diameter of 50 mm, a focal length of 40 mm, a lens material of S-LAH64, a refractive index of 1.788, and an Abbe number of for 47.49.

Further, the cylindrical mirror described in Step 3 is placed horizontally, and the cylindrical mirror described in Step 4 is placed vertically.

Further, the cylindrical lens described in step 5 is a high-order aspheric plano-convex cylindrical lens with a diameter of 10 mm and a focal length of 8 mm. The lens material is S-LAH64, the refractive index is 1.788, and the Abbe number is 47.49.

Further, the cylindrical mirror described in step 5 is placed vertically, and the two cylindrical mirrors described in step 4 and step 5 constitute a Kepler system, and the beam compression ratio is 5.

Further, the detector in step six is a rectangular detector for observing the quality of the outgoing beam.

Beneficial effect

The present invention utilizes a reasonable combination of Powell prisms and aspheric plano-convex cylindrical mirrors with different focal lengths to obtain a line light source with high power, high uniformity, high collimation, and ultra-narrow band, which can be applied to high-precision optical elements and chip testing. By increasing the number of long and short focus cylindrical mirrors, the line width of the line light source can be further compressed and the energy density of the line light source can be increased. The light source adopts the laser source to ensure the high power of the line light source. Using Zemax optical design software to analyze the design results, the results show that the linear light source compressed by a group of Kepler systems is parallel light, the beam distribution is very uniform, and the beam line width is 600um, which can well meet the actual needs and ensure detection And the high resolution and high precision performance of the display system.

Description of drawings

Fig. 1 is the optical path diagram of Powell prism expanded beam;

Fig. 2 is the overall optical path schematic diagram of the system of the present invention;

Figure 3 is the beam shape and illuminance diagram at different positions in the system;

Fig. 4 is a schematic diagram of the optical path of the compact structure of the present invention.

Detailed ways

The implementation of the present invention is described below through specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

Example 1

This embodiment is described in conjunction with FIGS. 1-3. A method for obtaining high power, high uniformity, high collimation, and ultra-narrowband line light source in this embodiment, as shown in FIG. 2, includes the following steps;

Step 1, the system light source 101 outputs a parallel laser beam;

Step 2, the light beam is incident on the Powell prism 102 to expand in the vertical direction;

Step 3, the expanded beam is incident on the cylindrical mirror 103, and the expanded beam is collimated so that the output beam is parallel light;

Step 4: The outputted strips of parallel light exit to another telephoto cylindrical lens 104, and the telephoto cylindrical lens 104 rotates 90° relative to the cylindrical mirror 103 to converge the strips of parallel light;

Step 5, the converging light beam is emitted to the short-focus cylindrical lens 105, and the outgoing light beam is corrected into a parallel light beam, thereby obtaining a high-power, high-uniformity, high-collimation, and ultra-narrow-band line light source;

Step 6. Place the detectors 106, 107, and 108 at different positions to check the quality and illuminance of the outgoing light beams at different positions of the system.

Combined with the design principle and design process, the above method is further explained:

Figure 1 shows the optical path diagram of the expanded beam of the Powell prism. The Powell prism can expand a circular beam in one direction, and the outgoing beam can be transformed into a line beam that diverges in the expanded direction. The beam is collimated by an aspheric cylindrical mirror into a long line beam with the same width as the original laser beam. After a set of cylindrical mirror system with Kepler structure, the collimated long line beam can be multiplied and compressed, and finally a very narrow band line beam with high collimation, high power and high uniformity can be obtained.

The optical system design software Zemax is used to analyze the designed system structure. Figure 3 is the beam shape and illuminance diagram at different positions in the system. It can be seen that the energy distribution of the final line beam emitted by the system is uniform, the collimation is high, and the line width is 600um.

Example 2

This embodiment is a compact system structure for obtaining high power, high uniformity, high collimation, and ultra-narrowband line light source.

In order to make the system more compact, reflectors are added to the above-mentioned method for obtaining high-power, high-uniformity, high-collimation, and ultra-narrow-band line light sources to refract the optical path, and the Kepler structure system is transformed into a Galileo system structure, as shown in Figure 4. Mirrors 109, 110, 111, 112, 113, 114 are added to the system. The plano-convex short-focus cylindrical lens 105 is adjusted to a plano-concave short-focus cylindrical lens 115, which makes the overall system more compact and smaller in size.

In actual operation, the number of reflectors is not limited to 4, and can be increased or decreased according to actual needs to make the system structure more reasonable.

In actual operation, the cylindrical mirror in this example can be replaced with a combination of different diameters and focal lengths, thereby changing the compression ratio of the system to the line beam width.

The present invention also can have other multiple embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations should be Belong to the scope of protection of the appended claims of the present invention.

Claims (8)

1. A method for obtaining a high power, high uniformity, high collimation, ultra-narrow band line source comprising the steps of:

step one, a system light source outputs a parallel laser beam;

step two, the light beam is incident to the Bawil prism to realize expansion in the vertical direction;

thirdly, the expanded light beam is incident to a cylindrical mirror, and the expanded light beam is collimated, so that an output light beam is parallel light;

step four, the output long parallel light is emitted to another long Jiao Zhumian mirror, and the long parallel light is converged;

step five, the converged light beam is emitted to a short-focus cylindrical mirror, and the emitted light beam is corrected to be a parallel light beam, so that a high-power, high-uniformity, high-collimation and ultra-narrow-band linear light source is obtained;

and step six, placing detectors at different positions to check the quality and illumination of the emergent light beams at different positions of the system.

2. The method of claim 1, wherein the light source in the first step is a high-performance white laser light source, the spot diameter is 2mm, and the output beam is approximately parallel light.

3. The method of claim 1, wherein the powell lens of step two has a ridge shape with a ridge angle of 60 °, the prism material being N-SF6, the refractive index of 1.805, and the abbe number of 25.36.

4. The method of claim 1, wherein the cylindrical lenses of the third and fourth steps are high order aspheric plano-convex cylindrical lenses having a diameter of 50mm, a focal length of 40mm, a lens material of S-LAH64, a refractive index of 1.788, and an abbe number of 47.49.

5. The method of claim 1 or 4, wherein the cylindrical mirror is positioned horizontally in step three and the cylindrical mirror is positioned vertically in step four.

6. The method of claim 1, wherein the cylindrical lens in the fifth step is a high order aspherical plano-convex cylindrical lens having a diameter of 10mm, a focal length of 8mm, a lens material of S-LAH64, a refractive index of 1.788, and an abbe number of 47.49.

7. The method of claim 1 or 6, wherein the cylindrical mirrors in the fifth step are disposed vertically, and the two cylindrical mirrors in the fourth and fifth steps form a kepler system, and the beam compression ratio is 5.

8. The method of claim 1, wherein the detector in step six is a rectangular detector for observing the outgoing beam quality.

Images