CN205027510U - High power optical glass measuring device - Google Patents

Abstract

The utility model discloses a device for measuring the transmittance of an optical lens, which comprises a light splitting sheet with a splitting ratio of 50/50, a compensation sheet, a slit, a first power meter and a second power meter. When measuring, first turn on the laser light source, record the readings P ₁ and P ₂ of the first power meter and the second power meter at this time, and obtain the power ratio c=P ₁ /P ₂ . Then, put the lens to be tested into the transmitted light path of the optical lens transmittance measuring device, adjust the position and angle of the lens to be tested by using the lens to be tested calibration device, and read the readings of the first power meter and the second power meter P ₁ ′ and P ₂ ′; finally, calculate the transmittance T of the lens to be tested by the following formula: T=P ₂ ′c/P ₁ ′. The utility model has lower requirements on the stability of the light source and no requirement on the thickness of the lens to be tested, and can eliminate the influences of the front and rear surface reflections of the light splitter, the uniformity of the film system of the optical coating lens, etc. on the test results.

Description

A high-power optical lens measuring device

technical field

The utility model belongs to the technical field of lasers, in particular to a high-power optical lens measuring device.

Background technique

The transmittance of an optical lens is an important reference quantity for reflecting the radiant light flux of an optical lens and evaluating the imaging quality, so its measurement is very important.

A lot of research has been done on the measurement of optical lens transmittance, and some progress has been made. In the past, the traditional single-channel measurement method was mostly used, that is, the ratio of the luminous flux obtained by the beam passing through the lens under test to the luminous flux obtained by the beam not passing through the lens under test. The single-channel test method has a simple structure and is easy to operate, but its biggest disadvantage is that this method will cause the radiant flux of the two tests to fluctuate due to the power fluctuation of the light source itself, which will cause the inaccuracy of the entire test.

In order to make up for the deficiency of the single-channel test system, a dual-channel test system can be used for transmittance testing. An existing test method is the spectrophotometer method. Although this method can accurately measure the lens transmittance, the lens transmittance is measured under low power conditions, and the lens itself is exposed to high-energy strong light. The characteristics in the illuminated state are likely to change, so the test in the low power state cannot account for the high power situation. In addition, when measuring with a spectrophotometer, there are often requirements for the thickness of the lens to be tested, and the lighting area on the lens is relatively small.

Another existing test device is shown in FIG. 1 , which can use a transmitted light path and a reflected light path to test the transmittance of a lens under high power conditions. Although this method abandons the influence of the stability of the light source itself and can be measured in a high-energy state, it can be seen from Figure 1 that the spectroscopic sheet has two surfaces, the front and the back, and the reflected light includes both the front surface reflection and the rear surface reflection. Light, because the optical path of the two is different, the power change trend caused by substrate absorption and so on is also different. If it is not treated differently, it will introduce errors to the test results. In addition, when the angle and position of the lens to be tested are changed, the incident angle and irradiation position of the laser will be changed indirectly, so that the transmittance of the lens itself will change slightly. Therefore, when measuring the transmittance of multiple lenses to be tested, The position and angle of each slice needs to be calibrated.

On the other hand, the level of transmittance is not only affected by the optical lens itself (internal air bubbles, dirt, etc.), but also by the uniformity of the film system on the coated lens. It is very likely that the transmittance measured at different positions will be significantly different. Therefore, it is not possible to obtain very accurate transmittance for large-aperture optical lenses, which requires measuring the large-aperture transmittance of the lens.

Utility model content

(1) Technical problems to be solved

The utility model aims to effectively eliminate the influence of factors such as instability of light source power, front and rear surface reflections of the beam splitter, uniformity of the film system of the coated lens on the measurement result of the transmittance of the optical lens and the repeatability of the measurement result.

(2) Technical solution

The utility model proposes an optical lens transmittance measuring device, which includes a beam splitter with a split ratio of 50/50, a compensation sheet, a slit, a first power meter, and a second power meter, wherein the split ratio is 50/50 The beam splitter of 50 is used to receive the test laser and divide it into transmitted light and reflected light. The beam splitter has two opposite parallel reflective surfaces, one of which has a coating; the compensation sheet is placed on the beam splitter One side of the coated beam is used to receive and transmit one of the transmitted light and reflected light output by the beam splitter, so as to compensate for the substrate absorption of the laser output from the coated beam splitter; The laser reflected by the slit is restricted so that only the laser reflected from the reflective surface of the spectroscopic sheet is allowed to pass through; the first power meter is used to detect the power of the laser passing through the slit; the second power The meter is used to detect the power of the laser light transmitted from the lens to be tested.

According to a preferred embodiment of the present invention, the optical lens transmittance measuring device further includes a lens calibration device, which is used to calibrate the position and angle of the lens to be tested.

According to a preferred embodiment of the present invention, the device for calibrating the lens to be tested includes a laser marker, an aperture diaphragm and a reflector, wherein the laser marker outputs a laser for calibration, and the laser is reflected by the lens to be tested and passes through the The small hole diaphragm is incident on the reflector, and the position and angle of the lens to be tested make the laser light reflected by the reflector continue to return through the small hole diaphragm to complete the position and angle calibration of the lens to be tested.

According to a preferred embodiment of the present utility model, the optical lens transmittance measurement device further includes a sealing box, which is used to seal the optical path and components of the optical lens transmittance measurement device. The sealed box of the optical lens transmittance measuring device is filled with protective gas.

(3) Beneficial effects

The utility model proposes a high-power optical lens measuring device, which has relatively low requirements on the stability of the light source, and has no requirement on the thickness of the lens to be measured, and can eliminate the reflection of the front and rear surfaces of the spectroscopic sheet, the uniformity of the film system of the optical coating lens, etc. , and the large-aperture test of the transmittance of the lens to be tested can be realized through the beam expander.

Description of drawings

Fig. 1 is the scheme diagram of the existing optical lens transmittance test using a spectroscopic sheet;

Fig. 2 is the structural representation of the first embodiment of the high-power optical lens measuring device proposed by the utility model;

Fig. 3 is a schematic structural view of the second embodiment of the high-power optical lens measuring device proposed by the present invention.

detailed description

The high-power optical lens measurement device proposed by the utility model adopts dual optical paths and equal optical path measurement, including a beam splitter with a split ratio of 50/50, a compensation sheet, a calibration device for the lens to be tested, a slit, a first power meter and a second power meter. count.

The beam splitter with a split ratio of 50/50 is used to receive the test laser and split it into transmitted light and reflected light. The beam splitter has two opposite parallel reflective surfaces, one of which has a coating. The beam splitter with a splitting ratio of 50/50 is preferably a coated beam splitter with an angle of 45°, and is placed at an angle of 45° to the optical axis of the laser.

The compensation plate is placed on the coated side of the beam splitter for receiving and transmitting one of the transmitted light and the reflected light output by the beam splitter, so as to compensate the substrate absorption of the laser output from the coated beam splitter. The material and thickness of the compensation sheet are exactly the same as those of the spectroscopic sheet with a splitting ratio of 50/50, and it is placed at an angle of 45° to the laser light path.

The slit is used to confine the laser light reflected from the beam splitter, so as to only allow the laser light reflected from the reflective surface of the beam splitter to pass through.

The first power meter is used to detect the power of the laser light passing through the slit.

The second power meter is used to detect the power of the laser light transmitted from the lens to be tested.

The lens calibration device is used to calibrate the position and angle of the lens to be tested, so as to ensure that the position and angle of the lens to be tested are the same during multiple measurements, and eliminate the measurement error caused by different placement of the lens to be tested.

The lens to be tested is placed on the optical path of the transmitted light of the coated beam splitter.

One embodiment of the calibration device for the lens to be tested includes a laser marker, a small aperture diaphragm and a reflector. The laser marking instrument outputs laser for calibration. The laser is reflected by the lens to be tested and enters the reflector through the aperture diaphragm. Adjust the position and angle of the lens to be tested so that the laser reflected by the mirror continues to return through the aperture aperture. , to complete the position and angle calibration of the lens to be tested.

The light emitted by the laser source passes through the beam expander and then enters the beam splitter with a splitting ratio of 50/50. The reflected laser light is restricted by slits, allowing only the reflected light from the coating surface of the beam splitter to pass through and enter the first power count. The laser output transmitted through the lens to be tested is finally incident on the second power meter.

Preferably, the measuring device of the present utility model further includes a sealing box, which is used for sealing the above-mentioned components. The sealed box can be filled with N ₂ and other protective gases to prevent the influence of atmospheric environment and other factors on the test results.

The steps for measuring the transmittance of the lens to be tested are:

S1. Turn on the laser light source, record the readings P ₁ and P ₂ of the first power meter and the second power meter at this time, and obtain the power ratio c=P ₁ /P ₂ ;

S2. Put the lens to be tested into the transmitted light path of the measuring device, use the lens calibration device to adjust the position and angle of the lens to be tested, and read the readings P ₁ ' and P ₂ ' of the first power meter and the second;

S3. Calculate the transmittance T of the lens to be tested by the following formula:

T=P ₂ 'c/P ₁ '.

In order to make the purpose, technical solutions and advantages of the utility model clearer, the utility model will be further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

The structure of the first embodiment of the utility model is shown in Figure 2. 1 is the laser light source, which is used to generate high-power laser; 2 is the beam expander, which is used to shape and expand the laser beam emitted by the laser light source, so that the transmittance of the lens to be tested can be measured with a large aperture; 3 is the splitting ratio of The 50/50 beam splitter is used to receive the test laser output by the beam expander 2 and divide it into transmitted light and reflected light, and its coating surface is located on the laser output surface; 4 is a compensation sheet for receiving and transmitting the coating light The laser light transmitted by the plate 3 is used to compensate the substrate absorption of the laser light transmitted from the coated beam splitter 3; The laser light reflected by the coating surface of the beam splitter 3 passes through; 6 is the first power meter, which is used to detect the power of the laser light passing through the slit 5; 7 is the lens to be tested, which makes the laser light transmitted from the compensation sheet 4 pass The lens to be tested 7; 8 is a laser marking instrument for outputting red light laser, 9 is a small hole diaphragm, and 10 is a reflector, the laser marking instrument 8, the small hole diaphragm 9, and the reflective mirror 10 constitute the calibration of the lens to be tested. device to calibrate its position and angle when measuring the transmittance of different lenses to be tested; 11 is a second power meter, which is used to detect the power of the laser light transmitted from the lens to be tested; 12 is a sealed box, used to transmit the light beam The beam protection device 2, the coated beam splitter 3, the compensation sheet 4, the slit 5, the first power meter 6, the second power meter 11, the calibration device for the lens to be tested and the reflector 10 are sealed, and the lens is realized in a sealed _N2 environment Measurement of transmittance.

The light emitted by the laser light source 1 passes through the beam expander 2, and is incident on the coated beam splitter 3 with a 45° angle splitting ratio of 50/50. The reflected laser light is restricted by the slit 5, and only the reflected light on the coated surface of the beam splitter is allowed to pass through. , and incident to the first power meter 6 ; the transmitted laser passes through the compensation sheet 4 and is output, and finally incident to the second power meter 11 . By controlling the first wattmeter 6 and the second wattmeter 11 to be correlated, the test values of the first wattmeter 6 and the second wattmeter 11 at a certain moment can be recorded simultaneously. The whole device is placed in the sealed box 12 for testing, and is filled with N ₂ for protection, so as to prevent factors such as the atmospheric environment from affecting the test results.

The placement method of the calibration device for the lens to be tested is shown in Figure 2. The laser marker 8, the aperture diaphragm 9, and the mirror 10 are arranged symmetrically on both sides of the transmission light path; the laser marker 8 is located above the transmission light path, and the output The light is a visible laser visible to the naked eye, and its output light is placed at an angle of θ with the transmitted light path; the aperture diaphragm 9 and the reflector 10 are located below the transmitted light path, and the planes where the two are located are respectively (90°-θ) with the transmitted light path Arranged at an included angle, and the light that passes through the center of the small hole diaphragm 9 and forms an angle of -θ with the transmitted light path must pass through the center of the reflector, and the intersection point of this light and the output light of the laser marker 8 must be located on the optical axis of the transmitted light path , and this intersection is also the intersection of the rear surface of the lens to be tested and the optical axis. In this way, the light emitted by the laser marking instrument is incident on the rear surface of the lens to be tested, and by fine-tuning the angle and position of the lens to be tested, the reflected light can pass through the center of the aperture stop 9 and be incident on the surface of the mirror 10. After being reflected by the mirror, it returns to the original path. At this time, the angle and position of the lens to be tested are calibrated.

As shown in FIG. 2 , the optical paths of the reflected light path and the transmitted light path in free space are approximately equal.

Assuming that the thickness of the beam splitter 3 is d and the refractive index is n, the optical path of the laser light reflected from the coating surface of the beam splitter inside the lens is Due to the compensation effect of the compensation film, the transmitted light travels the optical path inside the lens is also In this way, the reflected laser and the transmitted laser travel the same optical path in the lens substrate of the same material. Even under the influence of cumulative effects such as high-energy irradiation and time lapse, the absorption of the substrate is roughly the same, which can ensure the accuracy of the test results to the greatest extent. .

As shown in Figure 2, the thickness of the coating beam splitter 3 is 5mm, and the refractive index is 1.5. Due to the compensation effect of the compensation film, the transmitted light travels the optical path inside the lens is also In this way, the reflected laser and the transmitted laser travel the same optical path in the lens substrate of the same material, and even under the influence of cumulative effects such as high-energy irradiation and time lapse, the substrate absorption will be approximately the same, which can guarantee the accuracy of the test results to the greatest extent. accuracy.

The test steps for the transmittance of the lens to be tested are as follows:

S1. Turn on the power of the laser light source 1, record the readings P ₁ and P ₂ of the first power meter 6 and the second power meter 11 at this time, obtain the power ratio c=P ₁ /P ₂ , and turn off the power of the laser light source 1.

S2. Put the lens 7 to be tested into the transmission light path, and use the red laser marking instrument 8, the small hole diaphragm 9 and the reflector 10 for total reflection of red light to calibrate the position and angle of the lens 7 to be tested. Turn on the power of the laser light source 1 again, read and record the readings P ₁ ′ and P ₂ ′ of the first power meter 6 and the second power meter 11 at this time.

S3. Calculate the transmittance T of the lens to be tested:

T=P ₂ ′/(P ₁ ′/c)=P ₂ ′c/P ₁ ′.

By changing the power of the laser light source 1 and repeating the above steps, the transmittance of the lens 7 to be tested under different power states can be obtained. The structure of the second embodiment of the present utility model is shown in Fig. 3 . The difference from the first embodiment is that the coated surface of the coated beamsplitter 3 of this embodiment is located on the laser input surface, and the compensation sheet 4 is used to receive and transmit the laser light reflected from the coated beamsplitter 3 to compensate for the reflected laser light. The substrate absorption of the laser is similar to that of the first embodiment. The thickness of the coated beam splitter 3 is 5mm, and the refractive index is 1.5. The optical path traveled by the transmitted light inside the dichroic lens is also Similarly, the reflected laser and the transmitted laser have the same optical path in the lens substrate of the same material. Even under the influence of cumulative effects such as high-energy irradiation and time lapse, the substrate absorption is roughly the same, which can ensure the accuracy of the test results to the greatest extent. . The steps of testing the transmittance of the lens to be tested are the same as those in the first embodiment, and will not be repeated here.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above descriptions are only specific embodiments of the utility model and are not intended to limit the utility model. For new models, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims (5)

1. an optical mirror slip Transmissivity measurement device, comprise splitting ratio be 50/50 light splitting piece, compensating plate, slit, the first power meter and the second power meter, wherein,

Described splitting ratio be the light splitting piece of 50/50 for receiving testing laser and being divided into transmitted light and reflected light, this light splitting piece has two relative parallel reflective faces, and one of them reflecting surface has plated film;

Described compensating plate is placed in the side with plated film of described light splitting piece, for receive and transmission light splitting piece export transmitted light and reflected light in one, with compensate from plated film light splitting piece export laser substrate absorb;

Described slit is used for retraining the laser reflected from described light splitting piece, only to allow to pass through from the laser with the reflective surface of plated film of described light splitting piece;

Described first power meter is for detecting the power of the laser by described slit;

Described second power meter is for detecting the power of the laser from lens transmission to be measured.

2. optical mirror slip Transmissivity measurement device as claimed in claim 1, is characterized in that, also comprise eyeglass calibrating installation, and it is calibrated for the position of carrying out eyeglass to be measured and angle.

3. optical mirror slip Transmissivity measurement device as claimed in claim 2, it is characterized in that, eyeglass calibrating installation to be measured comprises laser indicating apparatus, aperture and catoptron, wherein, described laser indicating apparatus exports the laser for calibrating, this laser incides catoptron by after lens reflecting to be measured by aperture, and the position of described eyeglass to be measured and angle make laser that this catoptron reflects continue through the former road of this aperture to return, complete lens position to be measured and angle calibration system.

4. optical mirror slip Transmissivity measurement device as claimed in claim 1, is characterized in that, also comprise seal box, and it is for sealing the light path of described optical mirror slip Transmissivity measurement device and element.

5. optical mirror slip Transmissivity measurement device as claimed in claim 4, is characterized in that, be filled with blanket gas in described seal box.