Method and apparatus for measuring parallelism of germanium window plate

Abstract

The invention provides a method and apparatus for measuring the parallelism of a germanium window plate. The apparatus comprises a helium-neon laser system, an inclination-adjustable platform and a reference plane for receiving the reflected laser and measurement and analysis software thereof. The method includes the steps of gluing the germanium window plate on a photoresist plate and placing on the platform, and adjusting the platform inclination so that the surface of the photoresist is perpendicular to the laser. The parallelism of the upper and lower surfaces of the germanium window is theta = arctan (A / L) / 2, wherein A is the laser reflection offset reflected by the upper surface of the germanium window plate, and L is the distance between the laser receiving plane and the germanium window plate. Visible laser is used to detect the parallelism of infrared germanium window plate. The apparatus has the advantages of relative simple structure and high measurement precision.

Description

technical field [0001] The invention belongs to the field of optical detection, in particular to a method and a device for measuring the parallelism of germanium windows. Background technique [0002] Light glue refers to the process of adhering two clean, smooth and consistent optical parts with a little pressure without any adhesive. After light glue, the two light glue surfaces are parallel to each other; It is a reference plate with high precision and used for photoresist products. [0003] The germanium window is a parallel plane window element in front of the detector in the infrared thermal imaging system; it plays the role of passing through the infrared band (8~14μm) and sealing the Dewar bottle, so the parallelism requirements for high-precision germanium windows It is very high (θ≤10″), but because germanium windows cannot pass through visible light, conventional visible light interferometry cannot be used. At present, high-precision measurement can only be measu...

AI Technical Summary

Problems solved by technology

[0003] The germanium window is a parallel plane window element in front of the detector in the infrared thermal imaging system; it plays the role of passing through the infrared band (8~14μm) and sealing the Dewar bottle, so the parallelism requirements for high-precision germanium windows It is very high (θ≤10″), but because germanium windows cannot pass through visible light, conventional visible light interferometry cannot be used. At present, high-precision measurement can only be measured by Xintian JJ2 digital 2″ optical dividing head, but This equipment is very expensive, and the measured parallelism is only the angle between the upper and lower surfaces of the germanium window, and does not include surface flatness information (for example, it cannot reflect the influence of the low center edge height of the germanium window surface on the parallelism). Inaccurate parallelism, so it is necessary to invent a high-precision measurement method and its device with a relatively simple structure

Images