Frequency Tunable Wire Lasers

Abstract

The present invention provides frequency tunable solid-state radiation-generating devices, such as lasers and amplifiers, whose active medium has a size in at least one transverse dimension (e.g., its width) that is much smaller than the wavelength of radiation generated and/or amplified within the active medium. In such devices, a fraction of radiation travels as an evanescent propagating mode outside the active medium. It has been discovered that in such devices the radiation frequency can be tuned by the interaction of a tuning mechanism with the propagating evanescent mode.

What is claimed is: 
     
         1 .- 40 . (canceled) 
     
     
         41 . A Terahertz amplifier, comprising an amplification region for amplifying an incoming radiation signal having a frequency in a range of about 1 THz to about 10 THz to generate an amplified signal, characterized by a transverse distribution of the amplified signal such that a fraction of said signal extends outside the amplification region as the radiation signal propagates along the amplification region, an input port for coupling said incoming radiation into said amplification region, an exit port for extracting said amplified signal from said amplification region, and a tuning element external to said amplification region, said element being movable relative to said amplification region for interacting with the amplified signal extending outside the amplification region so as to change a frequency of said amplified signal. 
     
     
         42 . A tunable radiation source, comprising: an incoherent radiation source having an active medium for generating radiation, at least a portion of said radiation propagating along the active medium as a propagating evanescent wave; and a frequency tuning element external to said incoherent radiation source, said frequency tuning element being movable relative to said incoherent radiation source for interacting with the propagating evanescent wave in order to adjust a transverse mode profile of the radiation in the active medium, thereby changing the frequency of the radiation.