Abstract
Optical isolation is important for protecting a laser from damage due to the detrimental back reflection of light. It typically relies on breaking Lorentz reciprocity and normally is achieved via the Faraday magneto-optical effect, requiring a strong external magnetic field. Single-photon isolation, the quantum counterpart of optical isolation, is the key functional component in quantum information processing, but its realization is challenging. In this chapter, we present all-optical schemes for isolating the backscattering from single photons. In the first scheme, we show the single-photon isolation can be realized by using a chiral quantum optical system, in which a quantum emitter asymmetrically couples to nanowaveguide modes or whispering-gallery modes with high optical chirality. Secondly, we propose a chiral optical Kerr nonlinearity to bypass the so-called dynamical reciprocity in nonlinear optics and then achieve room-temperature photon isolation with low insertion loss. The concepts we present may pave the way for quantum information processing in an unconventional way.
Highlights
Controlling the flow of light is extremely essential for quantum information processing in integrated optical circuits
Nonreciprocal photonic elements, such as optical isolators and circulators, processing and routing of photonic signals at ultralow light level, or single-photon level in integrated optical circuits has been attracting a lot of interest
Some feasible schemes based on chiral quantum optics have been proposed to realize nonreciprocity at the single-photon level [16, 17], and optical isolators and circulators have been experimentally demonstrated in full quantum regime [18, 19]
Summary
Controlling the flow of light is extremely essential for quantum information processing in integrated optical circuits. Dong et al proposed and experimentally realized a scheme to achieve a true single-photon non-reciprocity in a cold atomic ensemble [14]. Most of these devices cannot achieve high isolations, low losses, and compatibility with single-photon level at the same time. Some feasible schemes based on chiral quantum optics have been proposed to realize nonreciprocity at the single-photon level [16, 17], and optical isolators and circulators have been experimentally demonstrated in full quantum regime [18, 19]. XKerr-based optical isolators and circulators for high isolation, low loss, and an ultralow probe field at room temperature have been experimentally demonstrated [21]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
