Waveguide integration of a >4.7‐THz quantum‐cascade laser. Issue 2 (14th January 2023) - Nuttall, Eleanor
Abstract: Waveguide integration of terahertz quantum cascade lasers (THz QCLs) is demonstrated at frequencies above 4.7 THz. A precision micromachining technique, followed by diamond‐turning and electroless‐plating has been used to manufacture hollow rectangular waveguides with integrated diagonal feedhorns. It is shown that surface roughness at the ≈ 1 μ m $\approx {1}\, {\mu }\text{m}$ level is achieved, enabling outcoupling of radiation in the 4.75–5.05 THz band, with a divergence angle of < 5 ∘ ${<5^{\circ }}$ along the plane of the QCLs substrate. Abstract : The internal structure of a THz QCL waveguide module.