Advanced Semiconductor Laboratory
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Cathodoluminescence and electron source


By
Wenzhe Guo

December 24, 2016 - Posted in Discussion
Over the last few years, the III-nitride AlGaN materials have been used to achieve deep ultraviolet laser sources, which triggers many new developments in various domains. However, realizing high-performance deep UV laser based on current injection and optical pumping remains challenging since p-doping and ohmic contact formation are difficult to achieve and inefficient. An alternative approach is in the case of cathodoluminescence based on electron beam pumping. Cathodoluminescence is the emission of photons of characteristic wavelengths by high energy electron beam bombarding semiconductor material. But to realize a compact and portable deep UV laser pumped by e beam still remains unavailable.

The most important part in this laser system is electron source. Previously, cathode ray tube (CRT) was mostly used as the electron source. However, lack of focused function and high-quality beam, CRT can’t serve as the electron source to achieve deep UV laser with high power and high-quality beam. Thus, based on CRT, an electron gun has been developed, which would be the best candidate for pumping deep UV laser, shown in Fig. 1. Generally, an electron gun consists of filament, electrode, anode and lens. By controlling electron gun, electron beam with different sizes, currents, and energy, could be achieved to cause the lasing with photons of different power.

1.jpg

Reference

[1] A New Electron Beam Welding Gun. http://contest.techbriefs.com/2012/entries/machinery-and-equipment/2179.​





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