Optical nanofiber-based cavity induced by periodic air-nanohole arrays

Abstract

We experimentally realized an optical nanofiber-based cavity by combining a 1-D photonic crystal and Bragg grating structures. The cavity morphology comprises a periodic, triplex air-cube introduced at the waist of the nanofiber. The cavity has been theoretically characterized using FDTD simulations to obtain the reflection and transmission spectra. We have also experimentally measured the transmission spectra and a Q-factor of ~784(87) for a very short periodic structure has been observed. The structure provides strong confinement of the cavity field and its potential for optical network integration makes it an ideal candidate for use in nanophotonic and quantum information systems

Fabrication of a nanofiber Bragg cavity with high quality factor using a focused helium ion beam

“…Nanofiber cavities, which are optical microcavities embedded in nanofibers, have been developed to further improve the coupling efficiency [22][23][24][25][26]. We have recently developed nanofiber Bragg cavities (NFBCs) using a gallium-ion type focused ion beam (FIB).…”

“…However, the quality (Q) factors of the NFBCs were approximately 250. A cavity structure of air-nanohole arrays was very recently fabricated on a nanofiber [26,28]. However, the Q factors of the previously reported NFBCs have been limited to a value of several hundred [25,26].…”

Tailoring a nanofiber for enhanced photon emission and coupling efficiency from single quantum emitters

“…In this Letter, we propose a tailored optical nanofiber (TONF) for enhanced photon emission and coupling efficiency from single-quantum emitters. This tailored nanofiber is a nanofiber-based cavity [41] with a narrow, air-filled groove inside the cavity (Fig. 1).…”

“…Hence, the optical characteristics of this proposed structure are determined by both structures. We previously fabricated an optical nanofiber-based cavity induced by periodic air-nanohole arrays [41] with a high Q factor with very few grating periods. We used the same parameters for structure I as in our previous work ( Fig.…”

Imaging light scattered by a subwavelength nanofiber, from near field to far field

“…They have been attracting much interest since the 2000s, for biosensors [3], quantum information [4,5], coupling light to bigger structures (microspheres [6], photonic crystals [7], microdisks [8],...) to quantum emitters (cold atoms [9,10], CdSe quantum dots [11], nitrogen vacancy in diamond [12], hBN flakes [13], single molecules [14], ...). Nanofibers can also be processed [15][16][17], for instance into nanofiber cavities to enhance the coupling efficiency of an emitter on the surface into its fundamental mode [18]. More than just light wires, nanofibers confine the transverse electromagnetic field to the point that a longitudinal component appears [19], bonding the local polarization of light to its propagation direction; also known as spin-orbit coupling of light [20] or spin-momentum locking [21], this effect opens new possibilites in photonics [22,23].…”