阅读说明：本技术 一种中红外激光动态连续衰减装置 (Dynamic continuous attenuation device for mid-infrared laser ) 是由 李岩 李姜 *** 崔爽 于国权 方艳超 于洋 郭立红 王烨 于 2020-08-13 设计创作，主要内容包括：本发明公开一种中红外激光动态连续衰减装置,包括设置的激光光路上的连续衰减器,连续衰减器包括偏振衰减片和旋转驱动器,旋转驱动器能够带动偏振衰减片旋转调节角度,偏振衰减片与其所在的激光光路垂直,激光照射到偏振衰减片上,随着偏振衰减片角度的变化,可改变激光的透过率,当激光的偏振方向与偏振衰减片的透光方向平行时,激光的透过率最大,随着角度不断变化,激光的透过率呈连续衰减,直到激光的偏振方向与偏振衰减片的透光方向垂直时,达到最大衰减效果。本发明通过可连接调节偏振衰减片角度的连续衰减器,使激光可连续调节透过率,提高红外成像导引头的测试精度。(The invention discloses a dynamic continuous attenuation device for mid-infrared laser, which comprises a continuous attenuator arranged on a laser light path, wherein the continuous attenuator comprises a polarization attenuation sheet and a rotary driver, the rotary driver can drive the polarization attenuation sheet to rotate for adjusting the angle, the polarization attenuation sheet is vertical to the laser light path where the polarization attenuation sheet is arranged, the laser irradiates the polarization attenuation sheet, the transmittance of the laser can be changed along with the change of the angle of the polarization attenuation sheet, when the polarization direction of the laser is parallel to the light transmission direction of the polarization attenuation sheet, the transmittance of the laser is the maximum, and the transmittance of the laser is continuously attenuated along with the continuous change of the angle until the polarization direction of the laser is vertical to the light transmission direction of the polarization attenuation sheet, so that the maximum attenuation effect is achieved. The invention can continuously adjust the transmittance of the laser and improve the testing precision of the infrared imaging seeker by connecting the continuous attenuator for adjusting the angle of the polarization attenuation piece.)

1. The dynamic continuous attenuation device for the intermediate infrared laser is characterized by comprising a continuous attenuator (1) arranged on a laser light path, wherein the continuous attenuator (1) comprises a polarization attenuation sheet and a rotary driver, the rotary driver can drive the polarization attenuation sheet to rotate for adjusting the angle, and the polarization attenuation sheet is perpendicular to the laser light path where the polarization attenuation sheet is located.

2. The dynamic continuous medium infrared laser attenuation device according to claim 1, characterized in that at least two groups of said continuous attenuators (1) are arranged on the laser path, and each group of said continuous attenuators (1) independently adjusts and controls the movement of the polarization attenuation plate.

3. The dynamic continuous medium infrared laser attenuation device according to claim 2, characterized in that a reflective fixed attenuation sheet (2) is further disposed on the laser light path, and the reflective fixed attenuation sheet (2) is located in front of the continuous attenuator (1);

the reflection type fixed attenuation piece (2) and a laser light path where the reflection type fixed attenuation piece is located are arranged at an included angle, and the reflection type fixed attenuation piece (2) can reflect part of laser to the laser energy absorption pool (3).

4. The dynamic continuous medium infrared laser attenuation device according to claim 3, characterized in that the reflective fixed attenuation sheet (2) is detachably inserted.

5. The dynamic continuous medium infrared laser attenuation device according to claim 3, characterized in that a reflective band-pass filter (4) for filtering background infrared noise outside the laser spectrum is further disposed on the laser path, and the reflective band-pass filter (4) is located behind the continuous attenuator (1).

6. The dynamic continuous attenuation device of mid-infrared laser light according to claim 5, characterized in that the laser light path further comprises two light path rotating mirrors (5), and the light path rotating mirrors (5) are used for changing the direction of the laser light path.

7. The dynamic continuous medium infrared laser attenuation device according to claim 6, characterized in that the continuous attenuator (1), the reflective fixed attenuator (2), the reflective band-pass filter (4) and the optical path turning mirror (5) are arranged in an energy control cavity; the radiator of the laser energy absorption pool (3) is arranged outside the energy control cavity.

8. The dynamic continuous attenuation device of mid-infrared laser according to claim 6, characterized in that the reflective fixed attenuation sheet (2) is a sheet structure with a zinc selenide substrate coated with a chromium-nickel-iron alloy coating film;

the reflective band-pass filter (4) is a narrow-band coating film.

Technical Field

The invention relates to the field of laser, in particular to a dynamic continuous attenuation device for mid-infrared laser.

Background

The infrared imaging seeker acquires guidance information by detecting infrared radiation pneumatically heated by a target engine spray pipe, a tail flame and a skin, and the acting distance of the infrared imaging seeker is related to the sensitivity of the seeker and the meteorological condition of the external environment besides the infrared radiation intensity and the radiation spectrum characteristic of a target.

When a laser interference semi-physical simulation test is carried out on the infrared imaging seeker, attenuation control needs to be carried out on interference infrared laser so as to simulate the laser energy change process in the process that the guided missile approaches flight. According to the difference of the initial simulation distance, the dynamic range of the energy change is large, and the laser adopted in the internal field simulation test needs to be subjected to large dynamic attenuation through an attenuation mechanism so as to meet the test requirement.

The existing intermediate infrared laser attenuation is realized by fixing attenuation pieces, the attenuation multiplying power of each attenuation piece is constant, a corresponding number of attenuation pieces are arranged according to the required attenuation, and the traditional attenuation mode can only realize step-type attenuation and cannot realize continuous attenuation adjustment.

For those skilled in the art, how to implement continuous attenuation of laser light is a technical problem to be solved at present.

Disclosure of Invention

The invention provides a dynamic continuous attenuation device for mid-infrared laser, which realizes continuous attenuation of laser by a polarization attenuation sheet with continuously adjusted angle, and the specific scheme is as follows:

the utility model provides a dynamic continuous attenuating device of intermediate infrared laser, is including the continuous attenuator on the laser light path that sets up, continuous attenuator includes polarization attenuation piece and rotation driver, rotation driver can drive polarization attenuation piece rotation angle of adjustment, polarization attenuation piece is perpendicular with its laser light path that is located.

Optionally, at least two groups of the continuous attenuators are arranged on the laser path, and each group of the continuous attenuators independently adjusts and controls the movement of the polarization attenuation sheet.

Optionally, a reflective fixed attenuation sheet is further disposed on the laser light path, and the reflective fixed attenuation sheet is located in front of the continuous attenuator;

the reflection type fixed attenuation piece and the laser light path where the reflection type fixed attenuation piece is located form an included angle, and the reflection type fixed attenuation piece can reflect part of laser to the laser energy absorption pool.

Optionally, the reflective fixed attenuation sheet is detachably inserted and arranged.

Optionally, a reflective band-pass filter for filtering background infrared noise outside the laser spectrum is further arranged on the laser light path, and the reflective band-pass filter is located behind the continuous attenuator.

Optionally, the laser light path further includes two light path rotating mirrors, and the light path rotating mirrors are used for changing the direction of the laser light path.

Optionally, the continuous attenuator, the reflective fixed attenuator, the reflective band-pass filter, and the optical path turning mirror are disposed in an energy control cavity; the heat radiator of the laser energy absorption cell is arranged outside the energy control cavity.

Optionally, the reflective fixed attenuation sheet is a sheet structure with a zinc selenide substrate plated with a chromium-nickel-iron alloy coating film;

the reflective band-pass filter is a narrow-band coated film.

The invention provides a dynamic continuous attenuation device for mid-infrared laser, which comprises a continuous attenuator arranged on a laser light path, wherein the continuous attenuator comprises a polarization attenuation sheet and a rotary driver, the rotary driver can drive the polarization attenuation sheet to rotate for adjusting the angle, the polarization attenuation sheet is vertical to the laser light path where the polarization attenuation sheet is arranged, the laser irradiates the polarization attenuation sheet, the laser is polarized light, and a polarizing sheet has the functions of shielding and transmitting incident light and can enable one longitudinal light or transverse light to transmit and the other longitudinal light or transverse light to shield. The transmittance of the laser can be changed along with the change of the angle of the polarization attenuation sheet, when the polarization direction of the laser is parallel to the light transmission direction of the polarization attenuation sheet, the transmittance of the laser is the maximum, and the transmittance of the laser is continuously attenuated along with the continuous change of the angle until the polarization direction of the laser is vertical to the light transmission direction of the polarization attenuation sheet, so that the maximum attenuation effect is achieved. The invention can continuously adjust the transmittance of the laser and improve the testing precision of the infrared imaging seeker by connecting the continuous attenuator for adjusting the angle of the polarization attenuation piece.

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 some embodiments 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 schematic diagram of a dynamic continuous attenuator for mid-infrared laser according to an embodiment of the present invention;

FIG. 2 is a schematic diagram showing the attenuation of laser light after passing through two sets of continuous attenuators.

The figure includes:

the device comprises a continuous attenuator 1, a reflective fixed attenuation sheet 2, a laser energy absorption cell 3, a reflective band-pass filter 4 and a light path rotating mirror 5.

Detailed Description

The core of the invention is to provide a dynamic continuous attenuation device for mid-infrared laser, which realizes continuous attenuation of laser by a polarization attenuation sheet with continuously adjusted angle.

In order to make those skilled in the art better understand the technical solution of the present invention, the dynamic continuous medium infrared laser attenuation apparatus of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in fig. 1, a schematic diagram of a structure of a dynamic continuous attenuator for mid-infrared laser according to an embodiment of the present invention is shown, in which a dashed line a indicates a laser path, and laser enters and exits along a direction indicated by an arrow; the dynamic continuous attenuation device for the mid-infrared laser comprises a continuous attenuator 1 arranged on a laser light path, and the laser is attenuated by the connecting attenuator 1 and then is transmitted continuously; the continuous attenuator 1 comprises a polarization attenuation sheet and a rotary driver, the rotary driver can drive the polarization attenuation sheet to rotate and adjust the angle, the polarization attenuation sheet is perpendicular to a laser light path where the polarization attenuation sheet is located, and laser is attenuated by the polarization attenuation sheet and then continuously transmitted.

The polarizing plate has a function of shielding and transmitting incident light, and can transmit longitudinal light or transverse light, and shield the longitudinal light or the transverse light. The laser is a polarized light, the asymmetry of the vibration direction to the propagation direction is called polarization, the optical wave is an electromagnetic wave, and the propagation direction of the optical wave is the propagation direction of the electromagnetic wave.

The polarization attenuation plate attenuates laser by utilizing the polarization of the laser, the transmittance of the laser can be changed along with the rotation change of the angle of the polarization attenuation plate, and when the polarization direction of the laser is parallel to the light transmission direction of the polarization attenuation plate, the transmittance of the laser is the largest, and the attenuation effect on the laser is the smallest; along with the continuous change of the angle of the polarization attenuation piece, the polarization direction of the laser and the light transmission direction of the polarization attenuation piece form a certain included angle, the larger the included angle is, the more obvious the laser attenuation is, the transmittance of the laser is continuously attenuated in the process that the rotation included angle of the polarization attenuation piece is increased, and the maximum attenuation effect is achieved until the polarization direction of the laser is perpendicular to the light transmission direction of the polarization attenuation piece.

The invention can lead the laser to be capable of continuously adjusting the transmittance through the continuous attenuator which can be connected with and adjust the angle of the polarization attenuation sheet, and compared with the traditional method which only can realize step graded attenuation by utilizing a fixed attenuation sheet, the invention can realize continuous attenuation adjustment and improve the test precision of the infrared imaging seeker.

On the basis of the scheme, at least two groups of continuous attenuators 1 are arranged on a laser light path, each group of continuous attenuators 1 independently adjusts and controls the movement of a polarization attenuation sheet, the two groups of continuous attenuators 1 respectively comprise respective polarization attenuation sheets and a rotary driver, and the rotary driver can adopt a quick-response direct-current rotary servo motor.

By arranging two groups of continuous attenuators 1 which independently work and adjust, on one hand, the two groups of continuous attenuators 1 are overlapped to expand the adjusting range of laser attenuation, each group of continuous attenuators 1 can realize dynamic continuous attenuation change adjustment from far to near 20dB, and the two groups of continuous attenuators 1 are overlapped to realize 40dB dynamic continuous attenuation change adjustment, as shown in figure 2, the continuous attenuators are schematic diagrams of attenuation conditions of laser after passing through the two groups of continuous attenuators 1; in the other direction, the shaking condition under real conditions can be simulated through the rotating matching of the two groups of continuous attenuators 1; when the change of the visual axis of the infrared imaging seeker is required to be simulated to cause the change of the laser energy at the optical entrance pupil, the rapid flicker of the energy at the entrance pupil is realized through the rapid deflection of the continuous attenuator 1 at the back. The continuous attenuator 1 can be set correspondingly according to the needs, and can also be arranged in more groups along the laser light path.

Furthermore, the invention also arranges a reflection type fixed attenuation sheet 2 on the laser path, and the reflection type fixed attenuation sheet 2 is positioned in front of the continuous attenuator 1; the laser is firstly attenuated to a certain degree by the fixed attenuation sheet 2 and then enters the continuous attenuator 1 for continuous attenuation adjustment, and the range of laser attenuation adjustment is enlarged by the fixed attenuation sheet 2.

The number and the attenuation ratio of the fixed attenuation pieces 2 are correspondingly adjusted according to requirements, and three fixed attenuation pieces 2 are arranged as shown in fig. 1, so that the attenuation coverage in an energy range of 0 dB-45 dB can be covered.

The reflection type fixed attenuation piece 2 and the laser light path where the reflection type fixed attenuation piece is located are arranged in an included angle mode, when laser enters the reflection type fixed attenuation piece 2, one part of transmission continues to advance along the laser light path, the other part of the transmission is reflected, the reflection type fixed attenuation piece 2 can reflect part of laser to the laser energy absorption pool 3, the reflected light enters the laser energy absorption pool 3, and the reflected laser energy is absorbed by the laser energy absorption pool 3.

Specifically, the reflection-type fixed attenuation pieces 2 are detachably inserted, the number of the fixed attenuation pieces 2 is flexibly selected according to needs, and adjustment is convenient.

Preferably, the invention also arranges a reflective band-pass filter 4 on the laser path for filtering background infrared noise outside the laser spectrum, and the reflective band-pass filter 4 is positioned behind the continuous attenuator 1.

The laser is emitted from the continuous attenuator 1 and enters the reflective band-pass filter 4, background infrared noise outside a laser spectrum is filtered through the reflective band-pass filter 4, wide wave thermal radiation of the laser is filtered, and the laser is further purified before being finally emitted.

The laser light path of the invention also comprises two light path rotating mirrors 5, the light path rotating mirrors 5 are used for changing the direction of the laser light path, and as shown in the figure 1, the two light path rotating mirrors 5 are respectively used for incidence and emergence, and the continuous attenuator 1, the reflective fixed attenuation sheet 2 and the reflective band-pass filter 4 are arranged between the two light path rotating mirrors 5. The light path rotating mirror 5 can reflect laser, change the propagation direction of the laser, keep the incident direction of the laser parallel to the emergent direction by arranging the two light path rotating mirrors 5, and can also play a role in reducing the whole size of the device through the structure.

Specifically, the continuous attenuator 1, the reflective fixed attenuator 2, the reflective band-pass filter 4 and the light path rotating mirror 5 are arranged in the energy control cavity; the radiator of the laser energy absorption pool 3 is arranged outside the energy control cavity, and the laser energy absorption pool 3 can be quickly radiated after absorbing the energy of the laser and heating.

The reflection type fixed attenuation sheet 2 is a sheet structure with a zinc selenide substrate plated with a chromium-nickel-iron alloy coating film. Different attenuation multiplying powers are realized by controlling the coating transmittance, and the indexes are as follows:

effective clear aperture: not less than 10 mm; attenuation ratio: 2dB, 5dB, 10dB, 15dB, 20 dB.

The polarization attenuation plate is an infrared wire grid polarizer in a silicon substrate, and the indexes of the polarizer are as follows:

wavelength range: 3 to 5 μm

Extinction ratio: 1000:1 (in full wavelength range)

Average transmittance: 85 percent of

Installation diameter: phi 25mm

Effective clear aperture: phi 19mm

Thickness: 5.8mm

The attenuation multiplying factor calculation formula of the polarization attenuation is as follows:

in the formula:

b: attenuation factor (in dB);

θ: the angle of deflection.

According to the device index, the maximum extinction ratio of the polaroid is 1000:1, 30dB dynamic attenuation can be realized by theoretically utilizing the polaroid, 20dB dynamic attenuation can be realized by a single attenuation sheet in practical application, and the dynamic range of 40dB attenuation can be met by adopting two paths of intermediate infrared wire grid polaroids.

The reflective band-pass filter 4 is a narrow-band coating film.

In simulation test, the system is controlled and calculated to be close with a period of 10ms, and when the system is near a 1km distance position with a speed of 1km/s, the attenuation conversion rate is less than or equal to 8.8 dB/s.

At 0 °, the polarization angle conversion rate is maximized with the same attenuation conversion factor. When the maximum attenuation conversion rate of the system is less than or equal to 8.8dB/s, the deflection angle rates which should be achieved at different initial positions are as follows:

as can be seen from the above table, the requirement of rapid attenuation conversion is fulfilled, and the maximum rotating speed of the direct current rotary servo motor cannot be lower than 814 °/s under the limit condition.

According to basic parameters of a motor, the dynamic control of an attenuation system can meet the requirement of the attenuation change rate of laser at the position of a distance of 1000m when a target approaches at the speed of 1000 m/s; the dual-motor attenuation synchronous control can ensure the corresponding requirements of the functional requirements on incident light change caused by visual axis deflection.

Referring to fig. 1, the infrared laser dynamic continuous attenuation apparatus of the present invention is adopted to make the laser attenuation process as follows: after laser is emitted from the head of the laser, the laser deflects 90 degrees after passing through the first light path rotating mirror 5 and is guided into the energy control cavity, energy fixed attenuation is realized through the three-level reflection type fixed attenuation sheet 2, the three-level reflection type fixed attenuation sheet 2 can uniformly cover the energy range of 0 dB-45 dB, and the laser energy reflected by the three-level reflection type fixed attenuation sheet 2 is absorbed by the laser energy absorption pool 3 and is emitted to the outside; the continuous attenuator 1 adopts a quick-response direct-current rotary servo motor to drive the polarization attenuation sheets, and the energy of laser passes through each polarization attenuation sheet to realize the attenuation change process from far to near 20 dB; the two continuous attenuators 1 are matched with follow-up adjustment, and can simulate the rapid flicker of laser energy at an optical entrance pupil caused by the visual axis change of an infrared imaging seeker; before laser emission, a reflective band-pass filter 4 filters background infrared noise outside a laser spectrum; finally, the laser is reflected by another optical path turning mirror 5 to deflect 90 and then is emitted.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.