Demonstration of nitride-based lasers excited by electron beam (Conference Presentation)

The UV semiconductor-based laser sources are important for a variety of fields, including medical, mechanical processing, chemical processing, biology, and photonics. However, the development of UV-B and UV-C laser diodes is strongly hampered because of the difficulties with current injection technology such as the realization of both a high hole concentration and low resistivity p-type AlGaN with a high AlN molar fraction. Because laser oscillation from AlGaN, with a high AlN molar fraction, can be obtained under optical pumping, UV lasers with controllable wavelengths should be realized if this problem can be solved. One promising technique for avoiding these problems is the use of electron beam excitation. Till date, nitride semiconductor-based lasers have been designed to achieve population inversion of the carrier and to oscillate due to current injection. However, as previously discussed, it is difficult to achieve wavelengths in UV-B and UV-C using this method. The conductivity control of nitride semiconductors is unnecessary using electron beam excitation. Therefore, it would be possible to expand the wavelength region for the laser action of nitride semiconductor-based lasers from deep UV to infrared if a nitride semiconductor-based laser could be oscillated via electron beam excitation. In this study, nitride-based lasers excited by electron beam were investigated, and laser emission was observed for the first time from a GaInN/GaN and GaN/AlGaN-based MQWs excited by an electron beam.