100 THz bandwidth optical modulators via coherent absorption of metamaterial

All-optical signal processing is one of the rising fields to eliminate the disadvantages of optical–electrical – optical conversion and continuing advances in terabits per second communications for high-performance computing. All-optical modulation via Coherent Perfect Absorption is the control of the phase or intensity of one light beam by another. A device based on coherent absorption has the advantage of being compact, fast, and intrinsically low power while demonstrating large modulations of light. Using femtosecond laser with variable pulse duration we probe the limits of switching that exploits coherent absorption in nanostructured gold and diamond metamaterials. Higher switching contrast ratios and modulation bandwidth exceeding 100THz has been observed