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Title: Wavelength beam-combining of terahertz quantum-cascade laser arrays

Wavelength beam-combining of four terahertz (THz) distributed-feedback quantum-cascade lasers (QCLs) is demonstrated using low-cost THz components that include a lens carved out of a plastic ball and a mechanically fabricated blazed grating. Single-lobed beams from predominantly single-mode QCLs radiating peak power in the range of50−<#comment/>170mWare overlapped in the far field at frequencies ranging from3.31−<#comment/>3.54THz. Collinear propagation with a maximum angular deviation of0.3∘<#comment/>is realized for the four beams. The total power efficiency for the focused and beam-combined radiation is as high as25%<#comment/>. This result could pave the way for future commercialization of beam-combined monolithic THz QCL arrays for multi-spectral THz sensing and spectroscopy at standoff distances.

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Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
Optical Society of America
Date Published:
Journal Name:
Optics Letters
0146-9592; OPLEDP
Page Range / eLocation ID:
Article No. 1864
Medium: X
Sponsoring Org:
National Science Foundation
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