CN210776002U

CN210776002U - F40 large-numerical-aperture high-power laser diffraction limit collimating objective lens

Info

Publication number: CN210776002U
Application number: CN201921930005.9U
Authority: CN
Inventors: 肖向荣
Original assignee: Wuhan Aolai Photoelectric Technology Co Ltd
Current assignee: Wuhan Aolai Photoelectric Technology Co Ltd
Priority date: 2019-11-08
Filing date: 2019-11-08
Publication date: 2020-06-16
Anticipated expiration: 2029-11-08

Abstract

The utility model relates to a F40 big numerical aperture high power laser diffraction limit collimating objective sets gradually first lens, second lens, third lens along 915nm laser incident direction, and first lens is biconvex lens, and the second lens is plano-convex lens, and the third lens is biconvex lens, and first lens and the center interval d2 of second lens become 12.7mm, and the center interval d4 of second lens and third lens become 4.1mm, the utility model discloses the performance parameter who reaches is: the focal length is 40mm, the numerical aperture is 0.5, the entrance pupil diameter is 20mm, the aspheric collimating lens is almost close to the diffraction limit, and the wave aberration is less than 0.22 lambda. The utility model discloses be applied to laser micromachining system, can solve coaxial high tracking, the measurement problem of size such as processing back degree of depth to improve equipment instrument's intellectuality and precision level.

Description

F40 large-numerical-aperture high-power laser diffraction limit collimating objective lens

Technical Field

The utility model relates to a laser beam machining field, concretely relates to F100 high power laser multi-disc compound achromatic focusing objective.

Background

In recent years, with the development of laser technology, the field of laser processing application is becoming more and more extensive. The laser processing has incomparable advantages compared with the traditional processing, and has the advantages of high cutting speed, strong material practicability and wider processing range.

However, in the field of laser micromachining, coaxial real-time tracking of the focal position of laser passing through a micro-focusing objective lens and depth synchronous detection after machining are difficult to realize at present.

Disclosure of Invention

The utility model discloses a solve the defect that prior art exists, designed one kind and exported the big numerical aperture high power diffraction limit collimating objective of approximate collimated light beam with continuous spectrum light source.

The utility model adopts the technical proposal that:

the utility model provides a F40 big numerical aperture high power laser diffraction limit collimating objective lens which characterized in that, includes first lens, second lens, the third lens that sets gradually along the laser incident direction, first lens is biconvex lens, the second lens is plano-concave lens, the third lens is biconvex lens, distance between first lens and the second lens center is greater than the distance between second lens and the third lens center.

Further, the center thickness of the first lens is 5.8mm, the center thickness of the second lens is 5.7mm, and the center thickness of the third lens is 5.6 mm.

Further, the distance between the centers of the first lens and the second lens is 12.7mm, and the distance between the centers of the second lens and the third lens is 4.1 mm.

Further, the first lens comprises a first curved surface and a second curved surface, the radius of curvature of the first curved surface is 36.7mm, and the radius of curvature of the second curved surface is-36.7 mm.

Further, the second lens comprises a third curved surface and a fourth curved surface, the curvature of the third curved surface is zero, and the radius of curvature of the fourth curved surface is-20.1 mm.

Further, the third lens comprises a fifth curved surface and a sixth curved surface, the radius of curvature of the fifth curved surface is 36.7mm, and the radius of curvature of the sixth curved surface is-36.7 mm.

Furthermore, the optical parameters Nd1: Vd1 of the first lens are 1.4926/61.2123, the optical parameters Nd2: Vd2 of the second lens are 1.4926/61.2123, and the optical parameters Nd3: Vd3 of the third lens are 1.4926/61.2123.

The utility model has the advantages that: the utility model has the advantages of simple structure and low production cost, can realize outputting 915nm laser light source collimation through above-mentioned design to the light-emitting end of multimode fiber or single mode fiber is the example, and the continuous spectrum light source is emergent light beam for approximate collimated light beam behind the collimating objective of this invention, is convenient for with the integration such as infinitely distant microobjective, laser focusing objective of selling on the existing market.

Drawings

Fig. 1 is a schematic structural diagram of an optical system of the present invention;

fig. 2 is a wave front difference diagram of the present invention;

fig. 3 is a MTF (modulation transfer function) diagram according to the present invention.

Reference numerals: 1-a first lens; 11-a first curved surface; 12-a second curved surface; 2-a second lens; 21-a third curved surface; 22-a fourth curved surface; 3-a third lens; 31-a fifth curved surface; 32-sixth curved surface.

Detailed Description

In order to make the technical solution of the present invention more clearly and completely appear, the present invention is described in detail below with reference to the accompanying drawings.

As shown in fig. 1, an F40 large-numerical-aperture high-power laser diffraction limit collimator objective lens includes a first lens 1, a second lens 2, and a third lens 3 along the incident direction of laser light, where the first lens 1 is a biconvex lens, the second lens 2 is a plano-concave lens, and the third lens 3 is a biconvex lens.

The utility model discloses the performance parameter that will reach is: the focal length is 40mm, the numerical aperture is 0.5, the entrance pupil diameter is 20mm, the relative aperture is 1:0.5, the actual working distance is 0.65f, and the light passing wavelength is 915 nm.

In order to satisfy the above performance parameter requirements, the structural parameters of each lens in the present invention are further described below with reference to the following embodiments.

The distance between the centers of the first lens 1 and the second lens 2 was 12.7mm, and the distance between the centers of the second lens 2 and the third lens 3 was 4.1 mm. The first lens 1 is composed of a first curved surface 11 and a second curved surface 12, the curvature radiuses of the first curved surface 11 and the second curved surface 12 are 36.7mm and-36.7 mm respectively, the center thickness of the first lens 1 is 5.8mm, and the optical parameters Nd1: Vd1 are 1.4926/61.2123; the second lens 2 consists of a third curved surface 21 and a fourth curved surface 22, the curvature of the third curved surface 21 is zero, the curvature radius of the fourth curved surface 22 is-20.1 mm, the center thickness of the second lens 2 is 5.7mm, and the optical parameters Nd2: Vd2 are 1.4926/61.2123; the third lens 3 is composed of a fifth curved surface 31 and a sixth curved surface 32, the radiuses of curvature of the fifth curved surface 31 and the sixth curved surface 32 are 36.7mm and-36.7 mm respectively, the center thickness of the third lens 3 is 5.6mm, and the optical parameters Nd3: Vd3 are 1.4337/53.2179. The curvature radius, the distance between the centers of the first lens and the second lens, the distance between the centers of the second lens and the third lens, and the allowable tolerance range of the optical parameters of the materials are all +/-5%.

According to the data, the utility model discloses can regard as big scanning angle, high machining precision, long working distance objective in geometry optics.

As shown in FIG. 2 and FIG. 3, the utility model provides a F100 high power laser multi-disc compound achromatic focusing objective, its wave front difference is crescent from inside to outside in FIG. 2, but the wave front difference all is less than 0.22 lambda, is nearly close diffraction limit, and this has important effect to coaxial height tracking in the laser micromachining, measure the degree of depth after the processing to improve the intellectuality and the level of refinement of equipment instrument.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the framework and principles of the present invention are intended to be included within the scope of the present invention.

Claims

1. The utility model provides a F40 big numerical aperture high power laser diffraction limit collimating objective lens which characterized in that, includes first lens, second lens, the third lens that sets gradually along the laser incident direction, first lens is biconvex lens, the second lens is plano-concave lens, the third lens is biconvex lens, distance between first lens and the second lens center is greater than the distance between second lens and the third lens center.

2. The F40 large-na high-power laser diffraction limit collimator objective lens of claim 1, wherein the first lens has a central thickness of 5.8mm, the second lens has a central thickness of 5.7mm, and the third lens has a central thickness of 5.6 mm.

3. The F40 large-na high-power laser diffraction limit collimator objective lens of claim 1, wherein the distance between the centers of the first and second lenses is 12.7mm, and the distance between the centers of the second and third lenses is 4.1 mm.

4. The F40 large numerical aperture high power laser diffraction limit collimator objective lens of claim 1, wherein the first lens comprises a first curved surface and a second curved surface, the radius of curvature of the first curved surface is 36.7mm, and the radius of curvature of the second curved surface is-36.7 mm.

5. The F40 large numerical aperture high power laser diffraction limit collimator objective lens of claim 1, wherein the second lens comprises a third curved surface and a fourth curved surface, the curvature of the third curved surface is zero, and the radius of curvature of the fourth curved surface is-20.1 mm.

6. The F40 large numerical aperture high power laser diffraction limit collimator objective lens of claim 1, wherein the third lens comprises a fifth curved surface and a sixth curved surface, the radius of curvature of the fifth curved surface is 36.7mm, and the radius of curvature of the sixth curved surface is-36.7 mm.

7. The F40 large-numerical-aperture high-power laser diffraction limit collimator objective lens as claimed in claim 1, wherein the optical parameters Nd1: Vd1 of the material of the first lens are 1.4926/61.2123, the optical parameters Nd2: Vd2 of the material of the second lens are 1.4926/61.2123, and the optical parameters Nd3: Vd3 of the material of the third lens are 1.4926/61.2123.