Signal mixing in a multiple input transistor laser near threshold

A single-emitter multiple-input transistor laser has been realized and demonstrated in signal mixing, yielding in the stimulated-recombination region near laser threshold frequency conversion with simultaneously an electrical and optical output signal. In the unique nonlinear region of compression of the transistor I-V characteristics (β≡ΔIC∕ΔIB, βspon>βstim), input signals f1=2GHz and f2=2.1GHz are converted into mf1±nf2 ranging from 0.1to8.4GHz. Stimulated emission (enhanced recombination) changes the transistor into a special form of nonlinear element, a special form of electronic processor or “switch.”