Thermal relaxation of a laser illuminated field emitter

Abstract

The time dependence of the total emission current from a field emitter illuminated by a chopped cw laser beam has been measured in conditions where the emission of primary photoelectrons is negligibly small. When the laser beam is switched on, the emission current increases with a characteristic time that is found to be in close agreement with the thermal relaxation time of the field emitter, showing that the laser-induced increase in emission is primarily due to tip heating. The large temperature rise and short thermal relaxation time associated with laser heating make it a widely applicable technique for controlling the temperature of a field emitter.