Engineered far-fields of metal-metal terahertz quantum cascade lasers with integrated planar horn structures

F Wang (1) , I Kundu (2) , L Chen (2) , Lianhe Li (2) , Edmund H. Linfield (2) , A. Giles Davies (2) , S Moumdji (3) , R Colombelli (3) , J Mangeney (1) , J Tignon (1) , Sukhdeep S. Dhillon (1)

1 LPA - Laboratoire Pierre Aigrain
2 School of Electronics and Electrical Engineering
3 IEF - Institut d'électronique fondamentale

The far-field emission profile of terahertz quantum cascade lasers (QCLs) in metal-metal waveguides is controlled in directionality and form through planar horn-type shape structures, whilst conserving a broad spectral response. The structures produce a gradual change in the high modal confinement of the waveguides and permit an improved far-field emission profile and resulting in a four-fold increase in the emitted output power. The two-dimensional far-field patterns are measured at 77 K and are agreement in with 3D modal simulations. The influence of parasitic high-order transverse modes is shown to be controlled by engineering the horn structure (ridge and horn widths), allowing only the fundamental mode to be coupled out.

Mots clés: European Union; Horizon 2020

Domaines: Optique [physics.optics]; Science des matériaux [cond-mat.mtrl-sci]

F Wang, I Kundu, L Chen, Lianhe Li, Edmund H. Linfield, et al.. Engineered far-fields of metal-metal terahertz quantum cascade lasers with integrated planar horn structures. Optics Express, 2016, 24 (3), pp.9. ⟨10.1364/OE.24.002174⟩. ⟨hal-01277653⟩