Massachusetts Institute of Technology

T C Sollner

Brian F Aull

Kirby B Nichols

An electrooptical switch for modulating a bias light beam in response to a control beam. The switch includes a modulator for modulating the bias beam to produce an output light beam therefrom, the modulator having a variable transmissivity; a detector module for receiving the control beam and generating a control signal therefrom, the detector module exhibiting switching operation in response to the control beam; and an amplifier for amplifiying the control signal to modulate the transmissivity of the modulator.

Electrooptical switch with separate detector and modulator modules

An harmonic multiplier comprising a resonant-tunneling diode responsive to a fundamental frequency source oscillator for generating odd harmonics of said fundamental frequency. The resonant-tunneling diode has a current/voltage characteristics curve exhibiting antisymmetry about a zero-volt, zero-current origin and negative differential resistance with high current peaks and low current valleys.

Harmonic multiplier using resonant tunneling device

Coupled quantum wells in which charge carriers shift from well to well by means of tunneling transfer. The quantum wells are created by disposing a material with lower carrier energy between layers of material with higher carrier energy. The spacing between wells is thin enough to allow tunneling transfer. The coupling of the wells displaces energy levels so that a system of N coupled wells has a spectrum of N energy levels. Under the proper conditions, transistions from one energy level to another result in the shift of charge carriers from one well to another. Because the tunneling transfer process is very fast, electronic devices capable of operating at terahertz frequencies are possible. Transistors, lasers, and detectors of electromagnetic radiation employing coupled quantum wells are disclosed.

Growing community of inventors

Winchester, MA, United States of America

T C Sollner