Supplement 1: Cavity-based mid-IR fiber gas laser pumped by a diode laser

Supplemental-document Originally published in Optica on 20 March 2016 (optica-3-3-218

Broadband guidance of ultraviolet light in a hollow-core optical fibre

We report an anti-resonant hollow core fibre with broad-band ultraviolet guidance from 190 - 400 nm, except for a narrow high loss resonance band at 245 - 265 nm. The minimum attenuation is 0.13 dB/m at 235 nm and 0.16 dB/m at 325 nm. With an inscribed core diameter of ~ 12 $\mu$m, the fibre's bend loss was 0.22 dB per turn for a bend radius of 3 c

Emission and Nonradiative Decay of Nanodiamond NV Centers in a Low Refractive Index Environment

The nitrogen vacancy (NV) center is the most widely studied single optical defect in diamond with great potential for applications in quantum technologies. Development of practical single-photon devices requires an understanding of the emission under a range of conditions and environments. In this work, we study the properties of a single NV center in nanodiamonds embedded in an air-like silica aerogel environment which provides a new domain for probing the emission behavior of NV centers in nanoscale environments. In this arrangement, the emission rate is governed primarily by the diamond crystal lattice with negligible contribution from the surrounding environment. This is in contrast to the conventional approach of studying nanodiamonds on a glass coverslip. We observe an increase in the mean lifetime due to the absence of a dielectric interface near the emitting dipoles and a distribution arising from the irregularities in the nanodiamond geometry. Our approach results in the estimation of the mean quantum efficiency (∼0.7) of the nanodiamond NV emitters