High-frequency modulated light source for millimicrosecond magnitude fluorescence lifetime measurement

Abstract

The invention relates to a high frequency modulation light source used for measuring nanosecond magnitude fluorescence life. Wavelength of the light source can be changed from 940nm to 380nm, can be modulated by high frequency periodic signals from 10MHz to 50MHz, and can detect drive signals of the light source. The invention has the advantages of simple structure, convenient manufacture, small volume, and capable of putting the light source into a sample chamber of a fluorescence spectrometer. A general simple type crystal oscillator is adopted to provide high frequency square wave voltage with temperature stability magnitude from minus or plus 10ppm / 0 to minus or plus 50 DEG C for being taken as high frequency modulation signals, the high frequency square wave voltage is supplied to abase electrode of a triode to control electric current of a collecting electrode of the triode, and a light emitting diode is driven to shine. Fluctuation contrast ratio of outputted light intensity excels 0.5, and a buffer amplifier detects drive voltage of the light emitting diode, for providing an improved fluorescence life measurement for improved phase modulation method with stable referencesignals.

Description

technical field [0001] The invention belongs to the scope of modulated light sources of photoelectric combination technology, and relates to a high-frequency modulated light source for nanosecond-level fluorescence lifetime measurement. Background technique [0002] Fluorescence lifetime refers to the statistical average residence time of electrons in the excited state, which is an important parameter in the study of luminescent materials, as well as in the fields of chemistry and biology. According to different materials and different transition processes, the fluorescence lifetime value covers from femtosecond (fs, 10 -15 s) to milliseconds (ms, 10 -3 s) even longer ranges. Microsecond and millisecond life measurement technology is very mature. More difficult is the nanosecond (ns, 10 -9 s), picosecond (ps, 10 -12 s), femtosecond-level lifetime measurement. The measurement methods for fluorescence lifetimes on the order of nanoseconds to picoseconds mainly include ① ...

AI Technical Summary

Problems solved by technology

At present, ultrashort pulse lasers, light-emitting diodes modulated by nanosecond pulse signals, and other light sources with pulse widths at or better than nanosecond levels cannot meet the requirements due to low repetition frequency and large volume.

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