Final published version
Licence: CC BY: Creative Commons Attribution 4.0 International License
Research output: Contribution to Journal/Magazine › Journal article › peer-review
<mark>Journal publication date</mark> | 26/12/2016 |
---|---|
<mark>Journal</mark> | Optics Express |
Issue number | 26 |
Volume | 24 |
Number of pages | 13 |
Pages (from-to) | 30002-30014 |
Publication Status | Published |
Early online date | 16/12/16 |
<mark>Original language</mark> | English |
The field of terahertz (THz) waveguides continues to grow rapidly, with many being tailored to suit the specific demands of a particular final application. Here, we explore waveguides capable of enabling efficient and accurate power delivery within cryogenic environments (<4 K). The performance of extruded hollow cylindrical metal waveguides made of un-annealed and annealed copper, as well as stainless steel, have been investigated for bore diameters between 1.75 - 4.6 mm, and at frequencies of 2.0, 2.85 and 3.4 THz, provided by a suitable selection of THz quantum cascade lasers. The annealed copper resulted in the lowest transmission losses, <3 dB/m for a 4.6 mm diameter waveguide, along with 90° bending losses as low as ∼2 dB for a bend radius of 15.9 mm. The observed trends in losses were subsequently analyzed and related to measured inner surface roughness parameters. These results provide a foundation for the development of a wide array of demanding lowtemperature THz applications, and enabling the study of fundamental physics.