Emission control in broad periodic waveguides and critical coupling

Henri Benisty (1) , Omer Khayam (1) , Cyril Cambournac (1)

1 Laboratoire Charles Fabry de l'Institut d'Optique / Naphel

Broad periodic channel waveguides, with a corrugation on their edge, exhibit a remarkable structure in their dispersion diagram, in the form of stripes of minigaps, whose hyperbolic shape is demonstrated. Around the Brillouin zone edge, the contra-directional feedback borrows the geometry of Littrow diffraction. Spontaneous emission from a large subset of modes then acquires a strong modulation. Lasing on these modes, the so-called “Littrow lasing”, offers also the lowest lasing threshold of the open resonator system. Reviewing our recent studies of this system, we discuss slow light and critical coupling phenomena: for a properly adjusted contra-directional coupling, the bands become substantially flat in a sizable area of the dispersion diagram, opening various perspectives. The band engineering tools to master these phenomena and the physical implications in other domains are briefly reviewed.

Keywords: Waveguides; Photonic crystal; Laser; Open resonator; Slow light; Coupled-mode theory

Domains: Optics [physics.optics]

Henri Benisty, Omer Khayam, Cyril Cambournac. Emission control in broad periodic waveguides and critical coupling. Photonics and Nanostructures - Fundamentals and Applications, 2010, 8 (4), pp.210-217. ⟨10.1016/j.photonics.2010.02.005⟩. ⟨hal-00566710⟩