CN112180588A

CN112180588A - Large-view-field laser warning lens design method

Info

Publication number: CN112180588A
Application number: CN202010927780.XA
Authority: CN
Inventors: 王鹏涛; 宋方; 刘继锋
Original assignee: Xi'an Fang Yuanming Science And Technology Co ltd
Current assignee: Xi'an Fang Yuanming Science And Technology Co ltd
Priority date: 2020-09-07
Filing date: 2020-09-07
Publication date: 2021-01-05

Abstract

The invention relates to a design method of a large-view-field laser warning lens, and belongs to the field of laser warning optical design. Designing an optical field of view according to the geometric optical principle and the geometric relation of focal length, image height and field angle through S1; s2, designing a laser warning optical system by utilizing ZEMAX software; s3 optical material selection and lens processing requirements, the invention has the advantages that the problems of small field angle and large processing and assembling difficulty in the prior art can be avoided, and a multi-lens method is introduced, so that the difficulty can be reduced, large field detection can be realized, and the cost is reduced.

Description

Large-view-field laser warning lens design method

Technical Field

The invention provides a design method of a large-view-field laser warning lens, and relates to the field of laser warning optical design.

Background

The laser alarm device is used as an important component of the existing photoelectric countermeasure equipment and needs to realize large-range airspace alarm, so that a large-view-field optical system is extremely necessary, and two common optical systems are a single-lens type and a wide-angle lens type. However, the single-lens optical structure cannot realize a large field of view by matching with a photosensitive surface of only a few millimeters, and a wide-angle lens is generally applied to an imaging laser warning system, and the optical system structure is relatively complex and can be realized by generally needing 5 to 8 lenses. Therefore, a low-cost, simple and effective method for a large-field optical system is lacking in the prior art.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a design method of a large-field-of-view laser warning lens, so as to solve the problems of small field angle and high processing and assembling difficulty in the prior art.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a design method for a large-field laser warning lens is characterized by comprising the following steps:

s1, designing an optical field of view according to the geometric relation of focal length, image height and field angle according to the geometric optics principle;

s2, designing a laser warning optical system by utilizing ZEMAX software;

s3 optical material selection and lens processing requirements.

Further, the step S1 specifically includes: according to the geometrical optics principle, the optical field of view is designed according to the geometrical relation h ═ f tan (fov) of focal length, image height and field angle.

Further, the step S2 specifically includes: a laser warning optical system based on a negative-positive structure is designed through ZEMAX software, and a large field of view is guaranteed by a negative lens, namely a biconcave lens.

Further, the step S3 specifically includes: the initial damage threshold of the K9 glass material corresponding to the laser with the wave band of 1064nm is about 25J/cm²Much larger than the laser power we receive and constrains the various processing parameters of the lens.

The invention has the beneficial effects that: the design method of the large-view-field laser warning lens can solve the problems of small view field angle and high processing and assembling difficulty in the prior art, and a multi-lens method is introduced, so that the difficulty can be reduced, large-view-field detection can be realized, and the cost is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only one embodiment of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a diagram of the optical structure of the present invention.

FIG. 2 is a simulation schematic of the present invention.

FIG. 3 illustrates the bi-concave lens requirements of the present invention.

FIG. 4 shows the requirements of the filter lens of the present invention.

FIG. 5 is a diagram of the attenuating plate lens requirements of the present invention.

Fig. 6 illustrates the lenticular lens requirements of the present invention.

[ description of reference ]

1. A biconcave lens objective lens surface; 2. the biconcave lens is like a mirror surface.

Detailed Description

For better understanding of the present invention, reference will now be made to the following examples and accompanying drawings.

Referring to fig. 1-6, the present invention provides a method for designing a large-field laser warning lens, comprising the following steps:

step S1 specifically includes: according to the principles of geometric optics, the optical field of view is designed according to the geometric relationship h ═ f tan (fov) between the focal length, the image height and the field angle, and in general, the system field angle fov is determined, so that the design can be performed only in the remaining two variables, namely the focal length of the optical system and the image height, namely the radius of the photosensitive surface of the detector.

Step S2 specifically includes: a multi-lens optical structure is adopted to extend an optical path to realize the receiving function of the optical system, and the optical structure is determined after multiple times of simulation verification. Aiming at the requirement of 82.5 degrees of large visual field of an optical system, the length of a cylinder is limited to be 25mm, and the laser alarm optical system based on a negative-positive structure is designed through ZEMAX software. The negative lens, namely the biconcave lens, ensures a field of view of 82.5 degrees, so that light of 0-82.5 degrees can enter the optical system; the positive lens, i.e., the lenticular lens, functions to condense light. The light rays are diffused by the negative lens, then are filtered and attenuated by the inserted optical filter (1064nm) and the inserted attenuation sheet (T is 60%), and finally are converged on the photosensitive surface of the detector by the convergence of the two positive lenses. A specific simulation schematic diagram is shown in fig. 1.

Step S3 specifically includes: the initial damage threshold of K9 glass material corresponding to laser with wave band of 1064nm is about 25J/cm2, which is much larger than the laser power we receive, so the material is selected to be K9 glass. The requirements of each lens are restricted, wherein the thickness of the biconcave lens is 5.4mm, the curvature radius of an object plane is 6mm, the curvature radius of an image plane is 4mm, and the distance between the object plane and the image plane is 2 mm; the diameter of the optical filter is 8mm, and the thickness of the optical filter is 1.1 mm; the diameter of the attenuation sheet is 8mm, and the thickness of the attenuation sheet is 2 mm; the diameter of the lenticular lens piece is 8mm, the thickness of the outer edge is 1.6mm, and the curvature radius is 6.8 mm. The lens processing dimensions and curvature requirements are shown in fig. 2-6.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Although the terms large field of view, geometric optics, ZEMAX, etc. are used more herein, the possibility of using other terms is not excluded. These terms are used merely to more conveniently describe and explain the nature of the present invention and they are to be interpreted as any additional limitation which is not in accordance with the spirit of the present invention.

Claims

1. A design method for a large-field laser warning lens is characterized by comprising the following steps:

s2, designing a laser warning optical system by utilizing ZEMAX software;

s3 optical material selection and lens processing requirements.

2. The method for designing a large-field laser warning lens according to claim 1, wherein the step S1 specifically includes: according to the geometrical optics principle, the optical field of view is designed according to the geometrical relation h ═ f tan (fov) of focal length, image height and field angle.

3. The method for designing a large-field laser warning lens according to claim 1, wherein the step S2 specifically includes: a laser warning optical system based on a negative-positive structure is designed through ZEMAX software, and a large field of view is guaranteed by a negative lens, namely a biconcave lens.

4. The method for designing a large-field laser warning lens according to claim 1, wherein the step S3 specifically includes: the initial damage threshold of the K9 glass material corresponding to the laser with the wave band of 1064nm is about 25J/cm²Much larger than the laser power we receive and constrains the various processing parameters of the lens.