Proceedings of the 43rd International Field Emission Symposium
J. Phys. IV France 06 (1996) C5-147-C5-151
Measurements of Modulation of the Current in a Field Emitter caused by a LaserM. Brugat and M.J. Hagmann
Department of Electrical and Computer Engineering, Florida International University, Miami, FL 33199, U.S.A.
Numerical simulations suggest that laser illumination of a field emitter increases the tunneling curent due to a resonant interaction in which tunneling electrons exchange quanta with the laser. Thus, a laser may be used as a gate, and a time-varying current is produced if the laser is amplitude modulated. We have measured an RF tunneling current of 0.4 nA when the tungsten tip of a sealed field emitter tube is illuminated with a laser diode that is amplitude modulated at 1 MHz, and the DC curent is 5µA. The laser diode increases the DC curent by 270 nA, which is attributed to tip heating. However, the RF current (0.4 nA) has a period less than estimates of the thermal relaxation time.
© EDP Sciences 1996