Omniresonant Broadband Coherent Perfect Absorption (CPA) Apparatus, Method, and Applications

The present disclosure is directed to systems and methods for omniresonant broadband coherent perfect absorption of incoherent light over large bandwidths. The apparatus and methods that enable 100% effective optical absorption in a structure, irrespective of the material from which it is constructed, over a large, continuous bandwidth (omniresonance) in ultrathin devices. Specifically, we demonstrate achromatic optical absorption (omniresonance) in a planar Fabry-Pérot micro-cavity via angularly multiplexed phase-matching. By assigning each wavelength to an appropriate angle of incidence, the micro-cavity is rendered absorbing with continuous spectral range. For example, the linewidth of a single-order 0.7 nm wide resonance is de-slanted in spectral-angular space to become a 70 nm wide achromatic resonance spanning multiple cavity free spectral ranges. The embodied invention can have important applications in, e.g., harvesting solar energy, white-light micro-lasers, and other broadband resonantly enhanced optical effects.