Laser cathode ray tube with a semiconductor double-heterostructure screen

Room-temperature laser action has been achieved in a cathode ray tube (CRT) in which the target screen is a (GaAs) (GaAlAs) double-heterostructure (DH) single-crystal semiconductor. The light-beam direction is normal to the face of the tube, i.e., parallel to the pump-electron-beam direction and, hence, scannable in two dimensions. Electron-beam energy is 34 keV and threshold current is 700 µA, corresponding to a current density of about 5 A/cm
²
.