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arXiv · 2004.10895

An antipodal Vivaldi antenna for improved far-field properties and polarization manipulation of broadband terahertz quantum cascade lasers

Urban Senica·Elena Mavrona·Tudor Olariu·Andres Forrer·Mehran Shahmohammadi·Mattias Beck·Jérôme Faist·Giacomo Scalari
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Abstract

We present an antipodal Vivaldi antenna for broadband double metal waveguide terahertz quantum cascade lasers and frequency combs. Its exponentially curved flare profile results in an adiabatic in-plane mode expansion, producing an improved far-field with a single-lobed beam of (23{\deg}x19{\deg}) full width half maximum with an octave-spanning bandwidth. The antenna also acts as a wave retarder, rotating the polarization from vertical toward horizontal polarization by a frequency-dependent angle. The laser's emission spectrum and current-voltage characteristics are not affected, as well as frequency comb operation. Measurements agree well with numerical simulations, and the proposed antenna covers a broad spectral range (1.5-4.5 THz).

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Urban Senica, Elena Mavrona, Tudor Olariu, Andres Forrer, Mehran Shahmohammadi, Mattias Beck, Jérôme Faist, Giacomo Scalari. 2020-04-22. An antipodal Vivaldi antenna for improved far-field properties and polarization manipulation of broadband terahertz quantum cascade lasers. https://doi.org/10.1063/5.0004038

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