Fluorescence spectrophotometer based on optical integrating sphere

Abstract

The invention provides a fluorescence spectrophotometer based on an optical integrating sphere. The fluorescence spectrophotometer is constituted by a light source, a monochromator and an integrating sphere colorimetric utensil, wherein the integrating sphere colorimetric utensil is mainly constituted by a light-permeable substrate, a diffuse reflection layer and diaphragms; the diffuse reflection layer is arranged at the outer side of a spherical cavity constituted by the light-permeable substrate in a coating mode, and an incident light path intersects with an emergent light path in a coplanar mode. Incident light into each integrating sphere is reflected by the corresponding diffuse reflection layer multiple times and stimulates a sample, and characteristic absorption spectra are generated inside the integrating sphere; after being reflected by the diffuse reflection layers multiple times, generated characteristic absorption spectra are superposed at the emergent diaphragms and effectively absorbed; meanwhile, by utilizing the integrating sphere, measuring errors caused by variation of light shapes and divergence angles can be effectively restrained, experimental results indicate that under the equal line diameter condition, by means of the fluorescence spectrophotometer, the sensitivity and stability of a traditional colorimetric utensil based on the 'square shape' or 'cylindrical shape' can be improved by 3-10 times.

Description

technical field [0001] The invention relates to a fluorescence spectrophotometer based on an optical integrating sphere, which is especially suitable for the technical field of fluorescence spectrophotometry testing with very strict requirements on "sensitivity" and "detection limit". Background technique [0002] The sample vessels of traditional fluorescence spectrophotometers (referred to as "fluorescence vessels" here) mostly use "square" or "cylindrical" quartz glass vessels. The light part of the sample interacts with the excitation light, and the fluorescence generation efficiency is not high; ②Limited by the detector’s receiving angle, only a very small part of the generated fluorescence can be received by the detector, which eventually leads to a detection limit and limited sensitivity. [0003] In order to improve the sensitivity, the conventional method is to increase the optical path of the excitation light by "increasing the diameter of the fluorescent dish" or...

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Problems solved by technology

[0002] The sample vessels of traditional fluorescence spectrophotometers (referred to as "fluorescence vessels" here) mostly use "square" or "cylindrical" quartz glass vessels. The light part of the sample interacts with the excitation light, and the fluorescence generation efficiency is not high; ②Limited by the detector’s receiving angle, only a very small part of the generated fluorescence can be received by the detector, which eventually leads to a detection limit and limited sensitivity

Although these two methods can increase the traveling optical path of the excitation light, because the distance between the "light incident end" and the "light receiving end" is also extended, any of the "light incident end" and "light receiving end" Small changes in the position of one end, small changes in the light shape and divergence angle, and small changes in the traveling optical path will cause large measurement errors, which will affect the stability (or repeatability) of the measurement, resulting in the improvement of its sensitivity and detection limit. Limited

[0004] In addition, since the above two methods cannot allow all the samples to participate in the stimulated emission reaction, and only a very small part of the total fluorescence generated is detected, the degree of improvement in sensitivity, detection limit and data stability is very large. limited

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