Application of ultra-thin tapered optical fibers to efficient single photon sources (1.7 million single photons coupled to a single mode fiber) and Realization of a fiber-microsphere cavity at cryogenic temperature are reported.
Photons have been identified early on as a very good candidate for quantum technologies applications, as carriers of quantum information, either by polarization encoding, time encoding or spatial encoding. Quantum cryptography, quantum communications, quantum networks and quantum computing are some of the applications targeted by the so called quantum photonics. Nevertheless, it was also clear at an early stage that bulk optics for handling quantum states of light would not be the best option for these technologies. More recently, single photons, entangled photons and quantum light in general have been coupled to integrated approaches coming from classical optics in order to meet the requirements of scalability, reliability and efficiency for quantum technologies. In this article, we describe our recent advances using elongated optical nano-fibers. We also present our latest results on nanocrystals made of perovskites and discuss some of their quantum properties. Finally, we will discuss the general steps necessary in order to couple these nanoemitters efficiently with our photonic platform, based on tapered optical nanofibers.
A tapered optical fiber with subwavelength diameter waist, an optical nanofiber, provides a unique and all-fiber platform for manipulating atoms and photons. This paper presents some recent results towards quantum photonics on a nanofiber platform. In one direction, we demonstrate a quantum interface between trapped single atoms and fiber-guided photons using a nanofiber cavity. In the other direction, we demonstrate a polarized fiber-in-line quantum light source using a hybrid system of a single gold nanorod and single quantum dot deposited on a nanofiber.
In this talk, our recent activities for nanofiber-integrated single light emitters for photonic quantum network. First, we report the coupling of various single light emitters, including diamond nanocrystals with color centers and hexagonal Boron Nitride flakes, to ultra-thin tapered optical fibers (nano optical fiber) with a diameter as small as 300 nm, keeping the transmittance of the fiber more than 90%. Second, for further improvement of the coupling efficiency, we introduce our development of nanofiber Bragg cavity (NFBC) with the mode volume of under 1 mu m^3 and repeatable tuning capability over more than 20 nm at visible wavelengths. The improvement of Q factor using He-ion beam milling will also be reported.