Tunable Fiber‐Cavity Enhanced Photon Emission from Defect Centers in hBN

Abstract

Realization of quantum photonic devices requires coupling single quantum emitters to the mode of optical resonators. In this work, a hybrid system consisting of defect centers in few‐layer hexagonal boron nitride (hBN) grown by chemical vapor deposition and a fiber‐based Fabry–Pérot cavity is presented. The sub 10‐nm thickness of hBN and its smooth surface enable efficient integration into the cavity mode. This hybrid platform is operated over a broad spectral range larger than 30 nm and its tuneability is used to explore different coupling regimes. Consequently, very large cavity‐assisted signal enhancement up to 50‐fold and strongly narrowed linewidths are achieved, which is owing to cavity funneling, a record for hBN‐cavity systems. Additionally, an excitation and readout scheme is implemented for resonant excitation that allows to establish cavity‐assisted photoluminescence excitation (PLE) spectroscopy. This work marks an important milestone for the deployment of 2D materials coupled to fiber‐based cavities in practical quantum technologies.

Tailoring the Emission Wavelength of Color Centers in Hexagonal Boron Nitride for Quantum Applications

“…The recently discovered color centers hosted by two-dimensional (2D) hexagonal boron nitride (hBN) [ 20 ] have demonstrated DW factors as high as 82.4% [ 21 ] and quantum efficiencies of 87% at room temperature [ 22 ], alongside bright and pure single photon emission. Due to the 2D geometry of the host crystals, it is easily possible to integrate the emitters with waveguides and fiber networks [ 23 , 24 ]. In addition, the robustness of the emitters, their long-term stability, and a fast radiative decay lifetime allowing high repetition rates [ 21 , 25 ], has led to the general understanding that these emitters can be used in practical quantum information processing applications.…”

Fabry-Perot microcavity spectra have a fine structure

“…An optical microcavity is a miniature version of a FP cavity, where the two mirrors are now positioned at only a few wavelengths λ from each other and at least one of the mirrors has a radius of curvature R m 100λ. Microcavities can strongly confine the optical field, boost the light-matter interaction of intra-cavity emitters [3][4][5][6][7][8], and increase the collection efficiency and emitted fraction into the zero-phonon line [9].…”

Engineering of single-photon emitters in hexagonal boron nitride [Invited]

“…The planar resonator is composed of a macroscopic plane mirror and a glass fiber tip with a concave structure. The hBN film grown by CVD is placed on the plane mirror to form a hybrid quantum emitter fiber-cavity system [86] . Copyright 2021, The Authors.…”

“…The results demonstrate the feasibility of effective integration of quantum emitters and nanofibers in 2D materials. In subsequent studies, the quantum emitters in hBN are coupled to a hybrid system based on an optical fiber-based Fabry-Pérot cavity [86] . This hybrid platform operates in a wide spectral range greater than 30 nm and can be used to explore different coupling regimes.…”