Enhanced light absorption in Tamm metasurface with a bound state in the continuum

Abstract

We consider light absorption in a germanium grating placed on top of photonic-crystalline substrate. Such a system supports an optical Tamm state decoupled from the continuous spectrum with its frequency within the photonic band gap. We have demonstrated that application of the Tamm state makes in possible to engineer extremely narrow absorber which provides a 100% absorption in a semiconductor grating in the critical coupling regime. The proposed design may be used at both normal and oblique incidence at the telecom wavelength.

References in corpus (4)

• Interference traps waves in open system: Bound states in the continuum
• Critical coupling vortex with grating-induced high quality optical Tamm states
• Bound states with complex frequencies near the continuum on lossy periodic structures
• Resonant field enhancement in lossy periodic structures supporting complex bound states in the continuum