Powell prism demarcation laser for negative cylindrical surface beam expansion

Abstract

The utility model relates to the field of optical equipment, in particular to a negative cylindrical surface beam expanding Powell prism demarcation laser, which comprises a plano-concave negative cylindrical mirror, a Powell prism and a laser collimating mirror, and the plano-concave negative cylindrical mirror is arranged between the Powell prism and the laser collimating mirror. According to the utility model, the plano-concave negative cylindrical mirror is used, the diameter of the original small slow-axis light beam is enlarged, the effective action area of the curved surface of the Powell prism is increased, and the processing difficulty of the Powell prism is reduced, so that the production efficiency and the qualified rate of the Powell prism are greatly improved, and the product cost is reduced; and the application range of the Powell prism uniform line laser is expanded.

Description

Technical Field

[0001] The utility model relates to the field of optical equipment, in particular to a Powell prism line laser with negative cylindrical beam expansion. Background Art

[0002] In actual use, in order to ensure the beam quality in the width direction of the laser projection line, the fast axis of the laser tube beam is often used as the focusing direction of the lens line width, and the slow axis direction with low beam quality is used as the line length to expand the projection line length. The working principle of the Powell prism is to use a special conical surface to control the energy distribution of the laser Gaussian beam. Under the combined effect of the surface radius and the cone coefficient, the preset projection angle and uniformity are obtained. This curved surface can be easily completed with the surface design and curve formula output using optical CAD design software. The Powell prism cannot be rotated using the spherical lens cold processing method, and can only be achieved using reciprocating wire grinding and wire polishing methods to achieve the curved surface shape output by CAD. The processing and inspection are relatively difficult, and the requirements for the design of the mold and the grinding process are relatively high.

[0003] The spot size at the collimator exit is especially important in applications with long working distance and large depth of field (e.g. Figure 1 、 2 As shown in the figure, a short-focus aspheric mirror must be used to reduce the exit diameter of the collimated beam. However, due to the asymmetry of the fast and slow axes of the edge-emitting laser (EEL), the beam width in the slow axis direction is much smaller than that in the fast axis. Generally, the slow axis is only 1 / 5 to 1 / 3 of the fast axis beam diameter. If the fast axis beam diameter is set to 1mm, then the slow axis beam diameter will only be 0.2~0.3mm wide, which means that the effective curved surface area of ​​the beam is also only at this level. Under this size condition, it is almost impossible to control the surface shape and surface quality of the Powell prism by using cold working wire grinding and wire polishing. The processing difficulty is extremely high, the finished product yield of the Powell prism is low, and the production efficiency is low, resulting in increased costs and reduced output, limiting its application and market scope. Utility Model Content

[0004] Aiming at the problem that the curved surface of the Powell prism in the prior art is difficult to process, the utility model provides a Powell prism projection laser with negative cylindrical beam expansion.

[0005] The utility model is realized through the following technical solutions:

[0006] A negative cylindrical beam expansion Powell prism projection laser comprises a plano-concave negative cylindrical mirror, a Powell prism and a laser collimator, wherein the plano-concave negative cylindrical mirror is arranged between the Powell prism and the laser collimator.

[0007] Preferably, the plane of the plano-concave negative cylindrical mirror faces the laser collimating mirror.

[0008] Preferably, the concave surface of the plano-concave negative cylindrical lens faces the Powell prism.

[0009] Preferably, the material of the plano-concave negative cylindrical lens is N-BK7.

[0010] Preferably, the edge distance between the plano-concave negative cylindrical lens and the Powell prism is 3mm.

[0011] Preferably, the plano-concave negative cylindrical lens is installed by pressing ring or optical cement.

[0012] Compared with the prior art, the utility model has the following beneficial effects:

[0013] The utility model discloses a negative cylindrical lens beam expanding Powell prism projection laser, uses the plano-concave negative cylindrical lens, and after the plano-concave negative cylindrical lens expands the original slow axis light beam, the effective action area of the Powell prism curve increases under the quality of guaranteeing the original light beam projection, and the size parameter of the Powell prism can be optimized according to the effective action area of the curve, the Powell prism curve radius increases, which means that the bending degree of the prism curve becomes more gentle, and the demand for high-precision processing equipment can be reduced, the taper surface coefficient is reduced, which means that the taper angle becomes more close to parallel or slightly inclined, and the processing process is simplified to a certain extent, and high-precision processing is also more easily realized. Therefore, in the actual processing process, the processing difficulty of the Powell prism is reduced, the production efficiency and the qualified rate are greatly improved, and then the product cost is reduced, and the use range of the Powell prism uniform linear laser is expanded. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is the lens arrangement drawing of the original single Powell prism;

[0015] Figure 2 It is the projection schematic view of the original single Powell prism;

[0016] Figure 3 It is the lens arrangement drawing of the negative cylindrical lens beam expanding Powell prism projection laser of the utility model;

[0017] Figure 4 It is the projection schematic view of the negative cylindrical lens beam expanding Powell prism projection laser of the utility model.

[0018] In the drawing, 1, light source;2, plano-concave negative cylindrical lens;3, Powell prism. DETAILED DESCRIPTION

[0019] The utility model will be further explained in detail in connection with specific embodiments, which is the explanation of the utility model but not the limitation.

[0020] The Powell prism 3 is usually made of optical glass material with high refractive index and low scattering rate, and the main processing difficulty is the special curved surface design and high-precision processing requirement, and the accurate control of the curved surface radius and the conical surface coefficient is also a key link in the processing process.

[0021] The utility model discloses a kind of negative cylindrical surface beam expansion's Powell prism line projection laser, refer to Figure 3 、 4 , including flat concave negative cylindrical mirror 2, Powell prism 3 and laser collimating mirror, flat concave negative cylindrical mirror 2 is set between Powell prism 3 and laser collimating mirror, wherein, the plane of flat concave negative cylindrical mirror 2 is towards laser collimating mirror, the concave surface of flat concave negative cylindrical mirror 2 is towards Powell prism 3.Flat concave negative cylindrical mirror 2 as the key element of beam expansion is placed between Powell prism 3 and laser collimating mirror, plane is towards laser collimating mirror to ensure that beam maintains certain parallelism before entering prism, concave surface is used to expand beam.

[0022] The edge distance between flat concave negative cylindrical mirror 2 and Powell prism 3 is 3mm, and flat concave negative cylindrical mirror 2 is installed using pressing ring or optical cement.

[0023] After installing flat concave negative cylindrical mirror 2, the originally smaller slow axis beam diameter is expanded, the effective area of the curved surface of Powell prism 3 is increased, the radius of curvature of Powell prism 3 is increased, so as to reduce the processing difficulty of Powell prism 3, the production efficiency and the pass rate of Powell prism 3 are greatly improved, the product cost is further reduced, and the use range of the uniform line laser of Powell prism 3 is also expanded.

[0024] The original single Powell prism 3 line projection scheme is shown in Figure 1 、 2 , input beam diameter is 0.4mm, output line projection angle is 25 °, and line length energy uniformity is >85%, under the parameter condition, the curved surface radius R of Powell prism 3 is 0.2, the conical surface coefficient K is 5, and the effective working area of curved surface is only 0.4mm, which is very difficult to process and control.

[0025] The utility model discloses a kind of negative cylindrical surface beam expansion's Powell prism line projection laser, laser beam is first collimated by laser collimating mirror, then enters flat concave negative cylindrical mirror 2.Under the action of the concave surface of flat concave negative cylindrical mirror 2, beam is expanded, and is projected on Powell prism 3.Powell prism 3 converts the beam after expansion into uniform line laser output using its special curved surface design.Adding negative cylindrical surface beam expansion's Powell prism line projection laser after expansion (as shown in Figure 3 、 4As shown in the figure, the output line parameters are completely the same as the light beam formed by the single Powell prism 3, while the parameter R of the Powell prism 3 is 0.8, the conical surface coefficient K is -2, and the effective working area of the curved surface is 1.84mm, which is easier to process and control, so after the addition of the flat-concave negative cylindrical mirror 2, the quality of the light beam can be ensured, and the related parameters of the Powell prism 3 can be optimized, so that the Powell prism 3 is easier to process.

[0026] The above merely describes preferred embodiments of the present application, and is not intended to limit the technical scheme of the present application in any way. Those skilled in the art should understand that the technical scheme can be modified and replaced in several simple ways without departing from the spirit and principles of the present application, and these modifications and replacements are also within the protection scope of the claims.

Claims

1. A Powell prism line projection laser with negative cylindrical beam expansion, characterized in that The flat concave negative cylindrical lens (2), the Powell prism (3) and the laser collimating lens are included.

2. The negative cylindrical expanded beam Powell prism line projection laser of claim 1 wherein, The flat surface of the flat concave negative cylindrical lens (2) faces the laser collimating lens.

3. The negative cylindrical beam expanded Powell lens projected laser of claim 1, wherein, The concave surface of the flat concave negative cylindrical lens (2) faces the Powell prism (3).

4. The negative cylindrical expanded beam Powell prism line projection laser of claim 1 wherein, The material of the flat concave negative cylindrical lens (2) is N-BK7.

5. The negative cylindrical beam expanded Powell lens projected laser of claim 1, wherein, The edge distance between the flat concave negative cylindrical lens (2) and the Powell prism (3) is 3mm.

6. The negative cylindrical expanded beam Powell prism line projection laser of claim 1 wherein, The flat concave negative cylindrical lens (2) is installed by pressing ring or optical cement.

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