Superimposed Bragg gratings and entangled biphoton dispersion management

Abstract

Quantum optical integrated circuits have heralded a paradigm shift in the realm of quantum information processing. Integrated photonics technology now empowers the creation of intricate optical circuits on single chips. While optical integrated circuits used to pose formidable challenges for numerous quantum applications, they have, in recent times, evolved to satisfy stringent requirements across a spectrum of research and industrial domains. Today, it is imperative to delve into research aimed at both crafting and preserving quantum properties within photonic substrates. Superimposed Bragg grating structures have emerged as valuable components within optical applications, poised to play pivotal roles in the development of integrated circuits. Nevertheless, these structures exhibit an inherent drawback in the form of dispersion, which can potentially compromise the preservation of quantum states. In this study, we meticulously scrutinize the physical attributes of these structures to elucidate the factors contributing to undesirable dispersion effects. We also investigate the correlation between two photons at the termination point of the structure. The superimposed Bragg grating structure under scrutiny boasts periods of both 1 and 3 micrometers, an overall length of 100 micrometers, and radiates at a wavelength of 1.55 micrometers. By subjecting photons to this medium individually or in tandem and analyzing their correlation function, we aim to pinpoint elements that effectively safeguard the quantum properties inherent in the system. This research endeavor is poised to yield valuable insights that will substantially influence the design of quantum integrated circuits, enhancing their efficacy in computational tasks and quantum information processing.