Transformation of the multimode terahertz quantum cascade laser beam into a Gaussian, using a hollow dielectric waveguide.
We demonstrate that a short hollow dielectric tube can act as a dielectric waveguide and transform the multimode, highly diverging terahertz quantum cascade laser beam into the lowest order dielectric waveguide hybrid mode, EH(11), which then couples efficiently to the free-space Gaussian mode, TEM(00). This simple approach should enable terahertz quantum cascade lasers to be employed in applications where a spatially coherent beam is required.
Danylov
Andriy A
AA
Submillimeter-Wave Technology Laboratory, University of Massachusetts Lowell, Lowell, Massachusetts 01854, USA. andriy_danylov@student.uml.edu
Waldman
Jerry
J
Goyette
Thomas M
TM
Gatesman
Andrew J
AJ
Giles
Robert H
RH
Linden
Kurt J
KJ
Neal
William R
WR
Nixon
William E
WE
Wanke
Michael C
MC
Reno
John L
JL