Characteristics and applications of room temperature optically modulated electronic tunneling metal-metal junction barriers

Summary form only given. Several experimental observations for detection and mixing with metal barrier metal tunneling junctions have been verified by recent theoretical calculations. Negative differential resistance has also been observed in the I-V characteristics of such junctions. With the high speed and broad-band sensitivity many potential applications are anticipated as a result. We also have several recent theoretical and experimental results which have verified predictions obtained from an electronic tunneling model which assumes an instantaneous modulation of the Fermi levels at the frequency of the incident radiation. Most significant is an agreement obtained experimentally with theoretical calculations of the curvature in the I-V characteristics as a function of barrier thickness. The tunneling model can also explain recent mixing experiments in which a striking oscillatory behavior of the beat signal with bias was observed by E. Sakuma and K.M. Evenson (1974). Experimental verification has also been obtained for the special-case of rectification at 0.6328 μm. Using the tunneling model we have also shown that the rectified signal can change polarity at bias voltages which decreases as the incident radiation intensity increases resulting in a highly nonlinear optical response at such bias points. Several optoelectronic devices utilizing the unique characteristics of the MBM tunneling junctions will be discussed. In particular, the junctions have been used for the generation of ultrashort electrical pulses by rectifying picosecond laser pulses. It is anticipated that the polarity reversal characteristics which have been observed experimentally with picosecond pulses from a mode-locked Nd:glass laser can be used to generate bipolar electrical pulses, each of which is shorter than the incident laser pu