Perfect single-sided radiation and absorption without mirrors

• DOI: 10.1364/optica.3.001079
• Publication Date: 2016-09-20T20:13:09Z
• Authors: Hengyun Zhou; Bo Zhen; Chia Wei Hsu; Owen D. Miller; Steven G. Johnson; John D. Joannopoulos; Marin Soljačić
• Keywords: 0103 physical sciences; FOS: Physical sciences; 01 natural sciences; 7. Clean energy; Physics - Optics; Optics (physics.optics)

Highly directional radiation from photonic structures is important for many applications, including high power crystal surface emitting lasers, grating couplers, and light detection ranging devices. However, previous dielectric, few-layer designs only achieved moderate asymmetry ratios, a fundamental understanding of bounds on asymmetric arbitrary still lacking. Here, we show that breaking the 180$^\circ$ rotational symmetry structure crucial achieving highly radiation. We develop general temporal coupled-mode theory formalism to derive decay rates top bottom slab resonance with in-plane wavevector. Guided by this formalism, infinite achievable even without need back-reflection mirrors, provide numerical examples achieve ratios exceeding $10^4$. The emission direction can also be rapidly switched tuning wavevector or frequency. Furthermore, addition weak material absorption loss, such used perfect single-sided illumination, single-pass less than $0.5\%$ mirrors. Our work provides new design principles in photonics.