Investigation of a novel light source by fast opto-electronic device

Abstract

In this paper, a fast opto-electronic device is used to investigate a novel ultraviolet light source with an optical system. The ultraviolet light source is generated by dielectric barrier discharge in argon at low pressure. Experimental results indicate that the light source is uniform when the gas pressure is lower than 0.1 atm, however, localized discharge (discharge filament) can be observed when the gas pressure is 0.4 atm. The light emission signals from the discharge are detected by fast opto-electronic device (Hamamatsu H7826-01) with increasing the amplitude of the applied voltage. It is shown that the discharge at low voltage (slightly above the breakdown voltage) has two discharge pulses per half cycle of the applied voltage, and duration of each pulse is more than 1μs. The number of discharge pulses increases with increasing the applied voltage. An intensified charge coupled device (ICCD) is usually used to investigate the mechanism of the uniform discharge at low pressure. However, an optical system is used in our experiment. The optical system includes an image-forming block and a fast opto-electronic device. Spatially resolved measurement of the discharge can be achieved selectively. The research results indicate that the uniform light source is composed of many micro-discharges that distribute randomly on the electrode. The duration of the micro-discharge is about several tens nanoseconds. These results are of great importance for the generation and application of ultraviolet light source.