Testing methods for transmittance of commonly used optical glass lenses

In daily life, lenses can be seen everywhere, and transmittance is the core parameter to measure the quality of lenses. High transmittance means good imaging quality; low transmittance means poor imaging quality. Although the measurement of lens transmittance has achieved certain results after years of development, and various lens transmittance measuring instruments have appeared on the market, the accuracy and measurement requirements still require only one. Improve.

Photocurrent detection method The photocurrent detection method first requires two measurements. The photocurrent count values in the two states of being placed in and not being placed in the system under test are read out. This ratio is the transmittance of the system under test. Integrating sphere method The testing system of the integrating sphere detection method consists of two parts: 1. Collimation subsystem, its main function is to approximately convert the beam generated by the light source into a parallel beam. 2. The detector subsystem is the main measurement part of the entire system and consists of an integrating sphere, a selenium photocell and a galvanometer. Retroreflection detection method A major feature of the retroreflection detection method is that it is specially used to detect the transmittance of the infrared band, which can effectively avoid the interference of errors. The main difference between the retroreflection detection method and the above two methods is that it has two outgoing beams, one of which is used as the reference light and the final measured value is the reference value, and the other is the measuring light and the final measured value is the measured value. The transmittance of the measured object is the ratio of the measured value and the reference value. Optical fiber detection method The specific process of optical fiber detection method: the light generated by the light source enters the aperture in parallel after being collimated by the collimation system. The stray light is filtered out by the aperture. The beam changes the beam aperture size through the aperture, and then directly illuminates the The light is split on the spectroscope, and the two resulting lights are modulated by the chopper disk. The light reflected by the spectroscope is used for the reference optical path, and the light transmitted from the spectroscope is used for the measurement optical path.

RT7512 long-wave infrared spectrophotometer is used to test the transmittance and reflectance of flat optical lenses.

Features

1. The test band can reach 7.5μm-12.5μm

2. The instrument adopts a monochromator scheme instead of Fourier infrared transformation, so it has better measurement accuracy and better signal-to-noise ratio.

3. Can test flat lenses or prisms in the range of 0-60°

4. It has automatic displacement function of the detector, and the compensation displacement can reach 40mm. 5. Built-in polarizer, which can realize 7.5μm-12.5μm polarization state test.

product advantages

1. The incident angle range is 0-60° when testing transmittance.

2. There is beam displacement compensation for measuring thick samples.

3. There is a monochromator inside the instrument, which is not manufactured using Fourier transform infrared technology, so the noise level is better and the measurement accuracy is higher.

4. Built-in polarization component, and the polarization component has a full range of polarization

5. Sampling spacing can reach 0.5nm-100nm Product specifications Sample stage rotation step spacing 0.01° Wavelength sampling spacing 0.5-100nm Spot size 6.0×3.0mm Test accuracy ±0.2% Test repeatability ±0.1%