Compact type full spectrum optical measuring head device used for reflection difference spectral measurement

Abstract

The invention discloses a compact type full spectrum optical measuring head device used for reflection difference spectral measurement. The compact type full spectrum optical measuring head device used for the reflection difference spectral measurement comprises an incoming optical fiber, an off-axis parabolic reflector, a polarizer, a rotation compensator, a polarization analyzer, a first concave reflector, a second concave reflector and an outgoing optical fiber. An optical source enters through the incoming optical fiber and is transformed to a parallel or a converged light beam through the off-axis parabolic reflector. The parallel or the converged light beam is transformed to linear polarized light through the polarizer and signal modulation is carried out on the linear polarized light through the rotation compensator, and the modulated light irradiates on the surface of a test sample. After the light reflected through the test sample becomes the linear polarized light, the linear polarized light is converged on the inlet of the outgoing optical fiber after being reflected through the first concave reflector and the second concave reflector. A centre line included angle of a back and forth light beam formed between the off-axis parabolic reflector and the first concave reflector is smaller than 4 degrees. The compact type full spectrum optical measuring head device used for the reflection difference spectral measurement is small in size, light in weight, convenient to adjust, reliable in performance and capable of being used for on-line detection in the ultravacuum environment.

Description

technical field [0001] The invention relates to the field of precision testing technology and the field of surface optical characterization, in particular to an optical measuring device using reflection differential spectroscopy technology. Background technique [0002] Reflectance differential spectroscopy is an optical measurement technique with high sensitivity to surface optical anisotropy, which is widely used in scientific research and industrial production fields such as monitoring the growth and preparation of ultra-thin coatings, and analyzing the nanostructure of semiconductor surfaces. This technology analyzes the physical properties of the surface of an object or the interface between substances by detecting the change in the polarization state of polarized light after it passes through the surface of the test sample. It has the characteristics of non-contact, non-destructive measurement, and no special requirements for the measurement environment. [0003] The t...

AI Technical Summary

Problems solved by technology

The large-volume optical probe not only weakens the mobile performance of the device, but also limits the application of the device for online testing on the vacuum chamber to a certain extent.

[0004] Early compact optical probes used a convex lens to converge the input beam. Since the input beam has a wide spectral range, but the refractive index of the convex lens is different for different wavelengths of light, resulting in serious beam dispersion, and it is impossible to obtain a small spot on the surface of the test sample.

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