Fabry-Perot microcavity for diamond-based photonics

Abstract

Open Fabry-Perot microcavities represent a promising route for achieving a quantum electrodynamics (cavity-QED) platform with diamond-based emitters. In particular, they offer the opportunity to introduce high purity, minimally fabricated material into a tunable, high quality factor optical resonator. Here, we demonstrate a fiber-based microcavity incorporating a thick (> 10 µm) diamond membrane with a finesse of 17,000, corresponding to a quality factor Q ∼ 10 6 . Such minimally fabricated, thick samples can contain optically stable emitters similar to those found in bulk diamond. We observe modified microcavity spectra in the presence of the membrane, and develop analytic and numerical models to describe the effect of the membrane on cavity modes, including loss and coupling to higher-order transverse modes. We estimate that a Purcell enhancement of approximately 20 should be possible for emitters within the diamond in this device, and provide evidence that better diamond surface treatments and mirror coatings could increase this value to 200 in a realistic system.

Design and low-temperature characterization of a tunable microcavity for diamond-based quantum networks

“…[13][14][15][16] In recent years, the open Fabry-Perot microcavity 17 has emerged as a promising platform for diamond emitters. [18][19][20][21][22] Such a microcavity provides in-situ spatial and spectral tunability, while reaching strong field confinement due to its small mode volume V and high quality factor Q. Moreover, this architecture allows for the use of diamond slabs 23 in which the NV center can be relatively far removed from surfaces and thus exhibit bulklike optical properties, as required for quantum network applications.…”

“…Inserting a diamond membrane (which has a higher refractive index than air) will lower its effective reflectivity, reducing the finesse threefold. 21 The influence of these mechanisms is strongly dependent on the character of the mode in the cavity. The modes with a diamond-like character have an antinode at the air-diamond interface and therefore are most susceptible to scattering at the diamond surface.…”

Optimal design of diamond-air microcavities for quantum networks using an analytical approach

“…Using a transfer matrix model [19,29] we find the electric field distribution for both the air-like and the diamond-like modes, as shown in figures 2(a) and (b). If the cavity supports a diamond-like mode, the field intensity (proportional to nE max 2 [30]) is higher in the diamond-part, and vice-versa for the air-like mode.…”

“…We further assume that the NV center is optimally placed in the cavity. To include the effect of surface roughness we extend the Fresnel reflection and transmission coefficients in the matrix model as described in [19,[31][32][33] (see footnote 4). Figure 2(d) shows that the resulting emission into the ZPL is strongly dependent on the electric field distribution over the cavity, both for the cases with and without roughness of the diamond interface.…”

High mechanical bandwidth fiber-coupled Fabry-Perot cavity

“…1a), using a CO 2 laser ablation process [10,24]. Both mirror substrates are coated with a high reflectivity dielectric mirror (LASEROPTIK) with the reflection band centered at 1550 nm.…”