Phosphors are substances that can absorb light energy of a specific wavelength and emit it in the visible, infrared or ultraviolet regions of the spectrum. In the production of phosphor powders, spectrometric analysis systems are widely used. They allow us to evaluate the quality of the obtained powders, or to investigate the effect of various impurities (activators) on the resulting product. This is achieved by determining the wavelength of light absorbed by the phosphor and the wavelength of light emitted by it. To determine these wavelengths, it is necessary to obtain an excitation spectrum and a luminescence spectrum, respectively.
The problem or task
The goal was to develop a system for registration of luminescence spectra and the excitation of phosphor powders, which consists of two monochromators and a photodetector based on the CCD.
In the course of solving the problem, a system for the spectrometric study of luminescent powders was developed. It performs the following functions: recording the luminescence spectrum at a known excitation wavelength, recording the luminescence spectrum at an unknown excitation wavelength (using two monochromators), recording the excitation spectrum, recording the absorption spectrum. The system consists of two Solar Laser Systems M266 monochromators, a photodetector based on the HAMAMATSU S5463 CCD and a personal computer running the software. During operation it is necessary to control the parameters of the photodetector and individual elements of the monochromator, such as: diffraction gratings, optical filters, shutters, rotary mirrors. The algorithm of the program should take into account the automatic change of diffraction gratings and optical filters of the monochromator, depending on the wavelength of the spectrum used. The software is created in the NI LabVIEW programming environment using API functions provided by the hardware manufacturer. The API functions allow you to control the elements of a monochromator and a photodetector. The monochromators and the photodetector are controlled using the USB protocol. The developed system made it possible, with a limited budget, to create a system for studying luminescent powders, which includes various methods for obtaining spectra, including non-standard techniques used by the customer.