A test system for measuring pl spectrum and ple spectrum of fluorescent powder

Abstract

The invention discloses a test system for measuring a PL spectrum and a PLE spectrum of fluorescent powder. The test system introduces double-modulation and comprises a femtosecond laser, a phase locked amplifier, an optical grating spectrograph, an optical dynamometer and an optical path device, wherein the optical patch device comprises a reflection mirror, a lens, an attenuation sheet and a beam splitter; laser emitted by the femtosecond laser is divided into two paths, one path of the laser passes through the lens and focuses on a sample so as to enable the fluorescence generated by the measured sample to pass through a convex lens, focus in an incidence gap of a spectrograph and enter the spectrograph, and the other path of the laser passes through the optical dynamometer for detection. The signal input end of the phase locked amplifier is connected with the output end of a PMT detector, reference signal input end of the phase lock amplifier is connected with the TDG output end of the femtosecond laser, the output end of the phase locked amplifier is connected with a voltage converter, and the voltage converter is connected with an electronic system in the optical grading spectrograph. According to the invention, a monochromatic light capable of being continuously regulated and having a wavelength range of 200-2,000 nm is obtained, and besides, during signal detection, phase lock amplification and demodulation are added to improve the precision of testing the PL spectrum of the fluorescent powder.

Description

technical field [0001] The invention relates to the technical field of fluorescent powder parameter measurement equipment, in particular to a test system for measuring PL spectrum and PLE spectrum of fluorescent powder. Background technique [0002] Since Shuji Nakamura invented the first white light LED in 1996, new phosphors for LEDs have emerged in an endless stream, with structures ranging from relatively mature aluminate phosphors to silicates, nitrides, nitrogen oxides, silicates and other phosphors. Its spectrum has expanded from the earliest 550nm to the entire visible light range. White LEDs have developed from blue LEDs + YAG yellow phosphors to form white light to purple LEDs + RGB three-color phosphors, blue LEDs + yellow-green two-color phosphors, etc. Form, the color rendering index and luminous efficacy of the formed white LED are getting higher and higher, and have been commercialized and applied in many fields. With the progress of phosphor theory and materi...

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Problems solved by technology

At the same time, the spectroscopic method is used to measure the PL spectrum of the phosphor at this wavelength, and the luminescent performance and spectral characteristics of the phosphor can be obtained accordingly. This method is of great use in the study of the luminescent principle of the phosphor and the preparation of the phosphor. It is widely used to analyze the structure and luminescent principle of phosphor powder. This method has been used for decades in the field of phosphor powder materials and phosphor powder applications, and has achieved good results, but there are still some shortcomings. For example, in the study of phosphor powder When the concentration is very low, the emitted fluorescence is weak, which brings some troubles to the measurement. Some test systems are often not competent. Now the commonly used fluorescent powder PL and PLE measurement equipment generally use xenon lamp as the light source, because the xenon lamp is in the range of 450-480nm The inner spectrum fluctuates, which makes the PLE spectrum fluctuate in this region, and the luminous range of the currently used blue LED chip is generally within this range, which makes it impossible to achieve the chip and phosphor in the preparation of white LED. optimal choice

[0006] In the prior art, the test system as described in Chinese patent application CN201010262884.X is aimed at measuring and testing the PL spectrum of semiconductor devices, which has relatively large limitations; the test system composed of its various components has a high sensitivity. There are still deficiencies in terms of signal-to-noise ratio and signal-to-noise ratio, which can neither meet the test requirements of diversified phosphor testing, nor meet the requirements of higher sensitivity and signal-to-noise ratio

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