Engineering subwavelength-grating photonic integrated structures for quantum applications (invited)

Sánchez-Postigo, Alejandro; Ginel-Moreno, Pablo; Graham-Scott, Connor; Schmid, Jens H.; Wangüemert-Pérez, J. Gonzalo; Ortega-Moñux, Alejandro; Cheben, Pavel; Molina-Fernández, Íñigo; Schuck, Carsten.

Abstract

Quantum photonics has emerged as a key driver for advancing applications, such as quantum communication and sensing, that harness the potential of quantum effects beyond classical capabilities. Photonic integrated circuits favor such implementations by providing low loss and interferometric stability. Nonetheless, to fully leverage these advantages, two major challenges need to be addressed: highly efficient fiber-to-chip light coupling and waveguide-integrated single-photon detection. In this work, we utilize subwavelength grating (SWG) metamaterials to design (i) novel off-chip couplers enabling sub-decibel coupling efficiency and (ii) a new superconducting nanowire single-photon detector (SNSPD) concept featuring enhanced photon absorption and fast detection.