Optical properties refer to the physical properties of optical materials, components or systems when transmitted, reflected, refracted, scattered and polarized. These properties directly affect the working efficiency and imaging quality of optical equipment, so the detection of optical properties is very important in the fields of optical manufacturing, instrument detection, communication technology, laser system and so on.

The detection of optical properties usually includes many aspects, mainly including transmittance, reflectivity, refractive index, wavefront distortion, scattering loss, polarization characteristics and so on. Different testing items need to adopt corresponding testing methods and equipment.
　　First of all, light transmittance detection is an important index to measure the light transmittance of optical materials or components. The commonly used method is to measure the transmittance of the sample at a specific wavelength by spectrophotometer. The higher the light transmittance, the smaller the light absorption and scattering of the material, which is suitable for high-precision imaging systems such as lenses and filters.
　　Secondly, reflectivity detection is usually used to evaluate the reflectivity of optical surfaces. The mirror with high reflectivity needs to reflect the incident light as much as possible to reduce the energy loss, while the antireflection film requires the reflectivity to be as low as possible. The reflectivity at different wavelengths can be accurately measured by reflection spectrometer or ellipsometer.

Thirdly, refractive index detection is an important means to evaluate the basic optical parameters of optical materials. Refractive index determines the speed and direction of light propagation in materials, which is especially critical for lens design. Commonly used measurement methods include Abbe refractometer, prism coupling method and interference method.

In addition, wavefront distortion detection is used to evaluate the imaging quality of optical system. Common detection methods include interferometer (such as Tyman-Green interferometer and Fizeau interferometer) and Hartmann wavefront sensor. The smaller the wavefront distortion, the clearer the image, which is often used for quality control of high-precision optical systems.

In addition, scattering detection is used to analyze the light loss caused by optical surface roughness or internal impurities. Laser scatterometer or integrating sphere system can be used to quantify scattering intensity, which is especially important for lasers and high-energy optical systems.

Finally, the detection of polarization characteristics is used to evaluate the quality of optical elements such as polarizers and wave plates. The influence of polarization tester or Muller matrix measurement system on the polarization state of light can be detected.
　　To sum up, the detection of optical performance is a systematic and complicated process, involving multiple parameters and various devices. With the continuous development of optical technology, accurate and efficient detection methods will provide more reliable quality assurance for optical products and promote the in-depth application of optical technology in various fields.