Total-reflection White cell

Abstract

The invention provides a total-reflection White cell. The total-reflection White cell comprises three total-reflection lenses, the total-reflection lenses comprise rectangular prisms, and spherical lenses are arranged on the side faces where the inclined edges of the upper surfaces and the lower surfaces of the rectangular prisms are located; a main plane of the first total-reflection lens and a main plane of the second total-reflection lens are coincident with a front main focal plane of the third total-reflection lens, and meanwhile, a main plane of the third total-reflection lens is coincident with a front main focal plane of the first total-reflection lens and a front main focal plane of the second total-reflection lens; and a principal optic axis of the first total-reflection lens anda principal optic axis of the second total-reflection lens are located on the same plane as a principal optic axis of the third total-reflection lens, the plane is perpendicular to the right-angled edges of the three total-reflection lens, and the principal optic axis of the first total-reflection lens and the principal optic axis of the second total-reflection lens are symmetrical with respect to the principal optic axis of the third total-reflection lens. The total-reflection White cell adopts a total-reflection mode to realize reflection imaging, the theoretical reflectivity can reach 100%, and the loss rate is low; and total reflection has no spectral selectivity, the light loss rate of different wavelengths is the same, and the total-reflection White cell can be applied to an ultraviolet differential absorption method requiring broadband work.

Description

technical field [0001] The invention belongs to the field of gas detection, in particular to a total reflection White cell. Background technique [0002] Optical absorption method is one of the methods to detect the composition and concentration of gaseous pollutants in gas. The detection equipment used mainly includes three parts: light source, absorption cell and photoelectric sensor. The longer the optical path of the light passing through the measured gas, the more significant the signal obtained, the lower the detection limit, and the higher the detection accuracy. [0003] The White cell is a better gas absorption cell for multiple reflections of incident light, such as figure 1 As shown, the White cell uses three spherical mirrors with the same curvature radius to achieve multiple reflections of the beam, and the optical path can be adjusted by adjusting the number of reflections. However, the reflectivity of the reflector in the White pool is the main factor affect...

AI Technical Summary

Problems solved by technology

However, in the ultraviolet band with shorter wavelength (wavelength less than 400nm), usually only aluminum film reflective layer can be used, and the reflectivity can only reach about 85%.

As the number of reflections increases, the attenuation of light energy is very serious. For example, after 20 reflections, the light intensity attenuates to about 4% of the original, which greatly limits the number of reflections.

The dielectric film can also be used as the reflective layer, the reflectivity can reach about 99%, and multiple reflections can be realized, but the cost of the dielectric film is high on the one hand, and on the other hand, the working band is very narrow, generally only providing a bandwidth of about 10nm

In the ultraviolet differential absorption method that requires wide-band work, the application requirements cannot be met

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