We describe the design, fabrication, and spectroscopy of coupled, high Quality (Q) factor silicon nanobeam photonic crystal cavities. We show that the single nanobeam cavity modes are coupled into even and odd superposition modes, and we simulate the frequency and Q factor as a function of nanobeam spacing, demonstrating that a differential wavelength shift of 70 nm between the two modes is possible while maintaining Q factors greater than 10^6. For both on-substrate and free-standing nanobeams, we experimentally monitor the response of the even mode as the gap is varied, and measure Q factors as high as 200,000.
We demonstrate the design, fabrication and characterization of nanobeam cavities with multiple higher order modes. Designs with two high Q modes with frequency separations of an octave are introduced, and we fabricate such cavities exhibiting resonances with wavelength separations of up to 740 nm.
We experimentally demonstrate high Quality factor dual-polarized TE-TM photonic crystal nanobeam cavities. The free-standing nanobeams are fabricated in a 500 nm thick silicon layer, and are probed using both tapered optical fiber and free-space resonant scattering set-ups. We measure Q-factors greater than 10^4 for both TM and TE modes, and observe large fiber transmission drops (0.3 -- 0.4) at the TM mode resonances.
We demonstrate high optical quality factors in aluminum nitride (AlN) photonic crystal nanobeam cavities. Suspended AlN photonic crystal nanobeams are fabricated in sputter-deposited AlN-on-insulator substrates using a self-protecting release process. Employing one-dimensional photonic crystal cavities coupled to integrated optical circuits we measure quality factors up to 146,000. By varying the waveguide-cavity coupling gap, extinction ratios in excess of 15 dB are obtained. Our results open the door for integrated photonic bandgap structures made from a low loss, wide-transparency, nonlinea…
We demonstrate an add-drop filter based on a dual photonic crystal nanobeam cavity system that emulates the operation of a traveling-wave resonator and drops light on resonance to a single output port. Realized on an advanced SOI CMOS (IBM 45nm SOI) chip without any foundry process modifications, the device shows 16dB extinction in through port and 1dB loss in drop port with a 3dB bandwidth of 64GHz. To the best of our knowledge, this is the first implementation of a four-port add-drop filter based on photonic crystal nanobeam cavities.
We present results on electrically driven nanobeam photonic crystal cavities formed out of a lateral p-i-n junction in gallium arsenide. Despite their small conducting dimensions, nanobeams have robust electrical properties with high current densities possible at low drive powers. Much like their two-dimensional counterparts, the nanobeam cavities exhibit bright electroluminescence at room temperature from embedded 1,250 nm InAs quantum dots. A small room temperature differential gain is observed in the cavities with minor beam self-heating suggesting that lasing is possible. These results ope…
We investigate the design, fabrication and experimental characterization of high Quality factor photonic crystal nanobeam cavities in silicon. Using a five-hole tapered 1D photonic crystal mirror and precise control of the cavity length, we designed cavities with theoretical Quality factors as high as 14 million. By detecting the cross-polarized resonantly scattered light from a normally incident laser beam, we measure a Quality factor of nearly 750,000. The effect of cavity size on mode frequency and Quality factor was simulated and then verified experimentally.
We present design guidelines for realizing side-coupled photonic crystal nanobeam (PCN) cavities with efficient coupling to low order resonances through adjusting the overlap of the PCN cavity mode and a feeding bus waveguide in both physical and k-space. We show that optimal side-coupled configurations function at a non-zero k-vector offset between the bus waveguide and PCN cavity modes. The straightforward design of side-coupled PCNs with high contrast resonances opens the door to their practical implementation in multiplexed, on-chip photonic devices.
The parity-time symmetry (PT symmetry) breaking phenomenon is investigated in a coupled nanobeam cavity system. An exceptional point is observed during the tuning of the relation of the gain/loss and coupling strength of the closely placed nanobeam pairs. The PT symmetry concept can be applied to realize unidirectional light propagation and single mode operation lasers, which may allow for a new way to harness the optical signal in photonic integrated circuits. Otherwise, operating at this particular exceptional point, sensitivity of tiny perturbation detection can be enhanced greatly compared…
One-dimensional nanobeam photonic crystal cavities are fabricated in an Er-doped amorphous silicon nitride layer. Photoluminescence from the cavities around 1.54 um is studied at cryogenic and room temperatures at different optical pump powers. The resonators demonstrate Purcell enhanced absorption and emission rates, also confirmed by time-resolved measurements. Resonances exhibit linewidth narrowing with pump power, signifying absorption bleaching and the onset of stimulated emission in the material at both 5.5 K and room temperature. We estimate from the cavity linewidths that Er has been p…
We demonstrate the design, fabrication and characterization of nanobeam photonic crystal cavities in (111)-GaAs with multiple high quality factor modes, with large frequency separations (up to 740 nm in experiment, i.e., a factor of 1.5 and up to an octave in theory). Such structures are crucial for efficient implementation of nonlinear frequency conversion. Here, we employ them to demonstrate sum frequency generation from 1300 nm and 1950 nm to 780 nm. These wavelengths are particularly interesting for quantum frequency conversion between Si vacancy centers in diamond and the fiber optic netw…
We demonstrate high-efficiency, degenerate four-wave mixing in triply resonant Kerr $χ^(3)$ photonic crystal (PhC) nanobeam cavities. Using a combination of temporal coupled mode theory and nonlinear finite-difference time-domain (FDTD) simulations, we study the nonlinear dynamics of resonant four-wave mixing processes and demonstrate the possibility of observing high-efficiency limit cycles and steady-state conversion corresponding to $\approx 100$% depletion of the pump light at low powers, even including effects due to losses, self- and cross-phase modulation, and imperfect frequency matchi…
We present the design of a femtogram L3-nanobeam photonic crystal cavity for optomechanical studies. Two symmetric nanobeams are created by placing three air slots in a silicon photonic crystal slab where three holes are removed. The optical quality factor (Q) is optimized up to 52,000. The nanobeams' mechanical frequencies are higher than 600 MHz due to their femtogram effective modal masses. The optical and mechanical modes are dispersively coupled with a vacuum optomechanical coupling rate g0/2pi exceeding 200 kHz. The anchor-loss-limited mechanical Q of the differential beam mode is evalua…
Photonic crystal lasers operating at room temperature based on high Q/V nanobeam cavities have been demonstrated. We reported a large spontaneous emission factor (~0.97) by fitting the L-L curve with the rate equations.
The realization of topological edge states (TESs) in photonic systems has provided unprecedented opportunities for manipulating light in novel manners. The Su-Schrieffer-Heeger (SSH) model has recently gained significant attention and has been exploited in a wide range of photonic platforms to create TESs. We develop a photonic topological insulator strategy based on SSH photonic crystal nanobeam cavities. In contrast to the conventional photonic SSH schemes which are based on alternately tuned coupling strength in one-dimensional lattice, our proposal provides higher flexibility and allows ta…
Wavelength-scale, high Q-factor photonic crystal cavities have emerged as a platform of choice for on-chip manipulation of optical signals, with applications ranging from low-power optical signal processing and cavity quantum electrodynamics, to biochemical sensing. Many of these applications, however, are limited by the fabrication tolerances and the inability to precisely control the resonant wavelength of fabricated structures. Various techniques for post-fabrication wavelength trimming and dynamical wavelength control -- using, for example, thermal effects, free carrier injection, low temp…
Photonic crystal nanobeam cavities are versatile platforms of interest for optical communications, optomechanics, optofluidics, cavity QED, etc. In a previous work \cite{quan10}, we proposed a deterministic method to achieve ultrahigh \emph{Q} cavities. This follow-up work provides systematic analysis and verifications of the deterministic design recipe and further extends the discussion to air-mode cavities. We demonstrate designs of dielectric-mode and air-mode cavities with $Q>10^9$, as well as cavities with both high-\emph{Q} ($>10^7$) and high on-resonance transmissions ($T>95%$).
We present and experimentally demonstrate a slotted photonic crystal single nanobeam cavity in silicon. The slot geometry is exploited to achieve ultra-small effective mode volumes, ~0.025(λ/n)^3, more than an order of magnitude smaller than traditional nanobeam cavities. A continuous slot and a tapered photonic crystal design are implemented to achieve experimental quality factors near 10^4. This device structure offers a unique platform for achieving enhanced light-matter interactions and could be used to benefit a variety of applications including non-linear optics, cavity quantum electro-d…
We report on the design and the fabrication of 1D photonic crystal (PhC) nanobeam cavities with optical resonances around 800 nm, compatible with Rubidium, Cesium or Argon atomic transitions. The cavities are made of Indium Gallium Phosphide (InGaP) material, a III-V semi-conductor compound which has a large index of refraction ($n \simeq 3.3$) favoring strong optical confinement and small mode volumes. Nanobeam cavities with inline and side coupling have been designed and fabricated, and quality factors up to $2\times 10^4$ have been measured.
We present the design, the fabrication and the characterization of a tunable one-dimensional (1D) photonic crystal cavity (PCC) etched on two vertically-coupled GaAs nanobeams. A novel fabrication method which prevents their adhesion under capillary forces is introduced. We discuss a design to increase the flexibility of the structure and we demonstrate a large reversible and controllable electromechanical wavelength tuning (> 15 nm) of the cavity modes.
Photonic resonators allowing to confine the electromagnetic field in ultra-small volumes and with long decay times are crucial to a number of applications requiring enhanced nonlinear effects. For applications to integrated photonic devices on chip, compactness and optimized in-plane transmission become relevant figures of merit as well. Here we optimize an encapsulated Si/SiO$_2$ photonic crystal nanobeam cavity at telecom wavelengths by means of a global optimization procedure, where only the first few holes surrounding the cavity are varied to decrease its radiative losses. This strategy al…
The lasing behavior of one dimensional GaAs nanobeam cavities with embedded InAs quantum dots is studied at room temperature. Lasing is observed throughout the quantum dot PL spectrum, and the wavelength dependence of the threshold is calculated. We study the cavity lasers under both 780 nm and 980 nm pump, finding thresholds as low as 0.3 uW and 19 uW for the two pump wavelengths, respectively. Finally, the nanobeam cavity laser wavelengths are tuned by up to 7 nm by employing a fiber taper in near proximity to the cavities. The fiber taper is used both to efficiently pump the cavity and coll…
A systematic design approach for one-dimensional and crossed photonic nanobeam cavities for quantum dot integration
Institute for Photonic Quantum Systems (PhoQS), Center for Optoelectronics and Photonics Paderborn (CeOPP) and Department of Physics, Paderborn University（帕德博恩大学光子量子系统研究所、光电与光子学帕德博恩中心及物理系）
We outline the design for a photonic crystal resonator made in a hybrid Silicon/Lithium Niobate material system. Using the index contrast between silicon and lithium niobate, it is possible to guide and confine photonic resonances in a thin film of silicon bonded on top of lithium niobate. Quality factors greater than $10^6$ at optical wavelength scale mode volumes are achievable. We show that patterning electrodes on such a system can yield an electro-optic coupling rate of 0.6 GHz/V (4 pm/V).
Si3N4 is an excellent material for applications of nanophotonics at visible wavelengths due to its wide bandgap and moderately large refractive index (n $\approx$ 2.0). We present the fabrication and characterization of Si3N4 photonic crystal nanobeam cavities for coupling to diamond nanocrystals and Nitrogen-Vacancy centers in a cavity QED system. Confocal micro-photoluminescence analysis of the nanobeam cavities demonstrates quality factors up to Q ~ 55,000, which is limited by the resolution of our spectrometer. We also demonstrate coarse tuning of cavity resonances across the 600-700nm ran…
We demonstrate the fabrication of photonic crystal nanobeam cavities with rectangular cross section into bulk diamond. In simulation, these cavities have an unloaded quality factor (Q) of over 1 million. Measured cavity resonances show fundamental modes with spectrometer-limited quality factors larger than 14,000 within 1nm of the NV center's zero phonon line at 637nm. We find high cavity yield across the full diamond chip with deterministic resonance trends across the fabricated parameter sweeps.
We present the design, fabrication and characterization of high-\emph{Q} (\emph{Q}=36,000) polymeric photonic crystal nanobeam cavities made of two polymers that have an ultra-low index contrast (ratio=1.15) and observed thermo-optical bistability at hundred microwatt power level. Due to the extended evanescent field and small mode volumes, polymeric nanobeam cavities are ideal platform for ultra-sensitive biochemical sensing. We demonstrate that these sensors have figures of merit (FOM=9190) two orders of magnitude greater than surface plasmon resonance based sensors, and outperform the comme…
We first experimentally demonstrated a transverse magnetic (TM) mode laser in a Photonic crystal (PhC) slab structure at room temperature. This study proposes a PhC nanobeam (NB) cavity to support a high-quality-factor (Q-factor) TM mode. For a large and complete photonic bandgap, the PhC NB structures consist of large air holes in a thick dielectric slab. The PhC NB cavity was optimized numerically for a high-Q-factor TM mode of over 1,000,000 by reducing the radii of the air holes quadratically from the center to the edge of the PhC NB. A single TM mode lasing action was observed in an InGaA…
We present the design and fabrication of nanobeam photonic crystal cavities in single crystal diamond for applications in cavity quantum electrodynamics. First, we describe three-dimensional finite-difference time-domain simulations of a high quality factor (Q ~ 10^6) and small mode volume (V ~ 0.5 (λ/n)^3) device whose cavity resonance corresponds to the zero-phonon transition (637nm) of the Nitrogen-Vacancy (NV) color center in diamond. This high Q/V structure, which would allow for strong light-matter interaction, is achieved by gradually tapering the size of the photonic crystal holes betw…
Cavity optomechanical systems can be used for sensitive detection of mechanical motion and to control mechanical resonators, down to the quantum level. The strength with which optical and mechanical degrees of freedom interact is defined by the photon-phonon coupling rate $g_0$, which is especially large in nanoscale systems. Here, we demonstrate an optomechanical system based on a sliced photonic crystal nanobeam, that combines subwavelength optical confinement with a low-mass mechanical mode. Analyzing the transduction of motion and effects of radiation pressure we find a coupling rate $g_0$…
Photonic crystal cavities with bowtie defects that combine ultra-high Q and ultra-low mode volume are theoretically studied for low-power nanoscale optical trapping. By harnessing the localized heating of the water layer near the bowtie region, combined with an applied alternating current electric field, this system provides long-range electrohydrodynamic transport of particles with average velocities of 30 $\mathrm{μm/s}$ towards the bowtie region on demand by switching the input wavelength. Once transported to a given bowtie region, synergistic interaction of optical gradient and attractive …
We report on the design of nanohole/nanobeam cavities in ridge waveguides for on-chip, quantum-dot-based single-photon generation. Our design overcomes limitations of a low-refractive-index-contrast material platform in terms of emitter-mode coupling efficiency and yields an outcoupling efficiency of 0.73 to the output ridge waveguide. Importantly, this high coupling efficiency is combined with broadband operation of 9 nm full-width half-maximum. We provide an explicit design procedure for identifying the optimum geometrical parameters according to the developed design. Besides, we fabricate a…
We describe the design, fabrication, and characterization of a one-dimensional silicon photonic crystal cavity in which a central slot is used to enhance the overlap between highly localized optical and mechanical modes. The optical mode has an extremely small mode volume of 0.017 $(λ_{vac}/n)^3$, and an optomechanical vacuum coupling rate of 310 kHz is measured. With optical quality factors up to $1.2 \cdot 10^5$, fabricated devices are in the resolved-sideband regime. The electric field has its maximum at the slot wall and couples to the in-plane breathing motion of the slot. The optomechani…
Triply Resonant Photonic Crystal Nanobeam Cavities for Unconditional Photon Blockade
Department of Physics, University of Washington（华盛顿大学物理系）；Department of Electrical and Computer Engineering, University of Washington（华盛顿大学电气与计算机工程系）；Pritzker School of Molecular Engineering, University of Chicago（芝加哥大学普里茨克分子工程学院）；CUNY Graduate Center（纽约市立大学研究生中心）；Department of Physics, University of Massachusetts, Dartmouth（麻省大学达特茅斯分校物理系）；Center for Scientific Computing and Data Science Research, University of Massachusetts, Dartmouth（麻省大学达特茅斯分校科学计算与数据科学研究中心）
A deterministic design of an ultrahigh Q, wavelength scale mode volume photonic crystal nanobeam cavity is proposed and experimentally demonstrated. Using this approach, cavities with Q>10^6 and on-resonance transmission T>90% are designed. The devices fabricated in Si and capped with low-index polymer, have Q=80,000 and T=73%. This is, to the best of our knowledge, the highest transmission measured in deterministically designed, wavelength scale high Q cavities.
A scalable approach for integrated photonic networks in single-crystal diamond using triangular etching of bulk samples is presented. We describe designs of high quality factor (Q=2.51x10^6) photonic crystal cavities with low mode volume (Vm=1.062x(λ/n)^3), which are connected via waveguides supported by suspension structures with predicted transmission loss of only 0.05 dB. We demonstrate the fabrication of these structures using transferred single-crystal silicon hard masks and angular dry etching, yielding photonic crystal cavities in the visible spectrum with measured quality factors in ex…
We demonstrate in simulation and experiment that the out-of-plane, far-field scattering profile of resonance modes in photonic crystal nanobeam (PCN) cavities can be used to identify resonance mode order. Through detection of resonantly scattered light with an infrared camera, the overlap between optical resonance modes and the leaky region of k-space can be measured experimentally. Mode order dependent overlap with the leaky region enables usage of resonance scattering as a "fingerprint" by which resonant modes in nanophotonic structures can be identified via detection in the far-field. By se…
We demonstrate off-resonant coupling between a single quantum dot and a nanobeam photonic crystal cavity, under resonant excitation of the quantum dot or the cavity. These results are consistent with previous descriptions of off-resonant coupling as an incoherent phonon-mediated process. The extension of this phenomenon to a nanobeam photonic crystal cavity presents interesting possibilities for coherent control of this interaction by tailoring the phonon density of states.
Diamond photonics provides an attractive architecture to explore room temperature cavity quantum electrodynamics and to realize scalable multi-qubit computing. Here we review the present state of diamond photonic technology. The design, fabrication and characterization of a novel triangular cross section nanobeam cavity produced in a single crystal diamond is demonstrated. The present cavity design, based on a triangular cross section allows vertical confinement and better signal collection efficiency than that of slab-based nanocavities, and eliminates the need for a pre-existing membrane. Th…
Engineering an array of precisely located cavity-coupled active media poses a major experimental challenge in the field of hybrid integrated photonics. We deterministically position solution processed colloidal quantum dots (QDs) on high quality-factor silicon nitride nanobeam cavities and demonstrate light-matter coupling. By lithographically defining a window on top of an encapsulated cavity that is cladded in a polymer resist, and spin coating QD solution, we can precisely control the placement of the QDs, which subsequently couple to the cavity. We show that the number of QDs coupled to th…
Tunable optical material properties enable novel applications in both versatile metamaterials and photonic components including optical sources and modulators. Transparent conductive oxides (TCOs) are able to highly tune their optical properties with applied bias via altering their free carrier concentration and hence plasma dispersion. The TCO material indium tin oxide (ITO) exhibits unity-strong index changes, and epsilon-near-zero behavior. However, with such tuning the corresponding high optical losses, originating from the fundamental Kramers-Kronig relations, result in low cavity finesse…
Integration of diamond nanobeams with SnVs on Al2O3 waveguides for scalable quantum photonic chip application
Fujitsu Limited（富士通有限公司）；Research Center for Advanced Science and Technology, University of Tokyo（东京大学先进科学技术研究中心）；Delft University of Technology（代尔夫特理工大学）
We describe the design, fabrication, and measurement of a cavity opto-mechanical system consisting of two nanobeams of silicon nitride in the near-field of each other, forming a so-called "zipper" cavity. A photonic crystal patterning is applied to the nanobeams to localize optical and mechanical energy to the same cubic-micron-scale volume. The picrogram-scale mass of the structure, along with the strong per-photon optical gradient force, results in a giant optical spring effect. In addition, a novel damping regime is explored in which the small heat capacity of the zipper cavity results in b…
One dimensional nanobeam photonic crystal cavities are fabricated in silicon dioxide with silicon nanocrystals. Quality factors of over 9 x 10^3 are found in experiment, matching theoretical predictions, with mode volumes of 1.5(lambda/n)^3 . Photoluminescence from the cavity modes is observed in the visible wavelength range 600-820 nm. Studies of the lossy characteristics of the cavities are conducted at varying temperatures and pump powers. Free carrier absorption effects are found to be significant at pump powers as low as a few hundred nanowatts.
GeSn alloys have been regarded as a potential lasing material for a complementary metal-oxide-semiconductor (CMOS)-compatible light source. Despite their remarkable progress, all GeSn lasers reported to date have large device footprints and active areas, which prevent the realization of densely integrated on-chip lasers operating at low power consumption. Here, we present a 1D photonic crystal (PC) nanobeam with a very small device footprint of 7 $μm^2$ and a compact active area of ~1.2 $μm^2$ on a high-quality GeSn-on-insulator (GeSnOI) substrate. We also report that the improved directness i…
The negatively-charged nitrogen vacancy center (NV) in diamond has generated significant interest as a platform for quantum information processing and sensing in the solid state. For most applications, high quality optical cavities are required to enhance the NV zero-phonon line (ZPL) emission. An outstanding challenge in maximizing the degree of NV-cavity coupling is the deterministic placement of NVs within the cavity. Here, we report photonic crystal nanobeam cavities coupled to NVs incorporated by a delta-doping technique that allows nanometer-scale vertical positioning of the emitters. We…
We present the design, fabrication and characterization of high quality factor silicon nitride nanobeam PhC cavities at visible wavelengths for coupling to diamond color centers in a cavity QED system. We demonstrate devices with a quality factor of about 24;000 around the zero-phonon line of the germanium-vacancy center in diamond. We also present an efficient fiber-to-waveguide coupling platform for suspended nanophotonics. By gently changing the corresponding effective indices at the fiber-waveguide interface, we achieve an efficiency of about 96% at the cavity resonance.
Photonic integrated circuits that are manufactured with mature semiconductor technology hold great promise for realizing scalable quantum technology. Efficient interfaces between quantum emitters and nanophotonic devices are crucial building blocks for such implementations on silicon chips. These interfaces can be realized as nanobeam optical cavities with high quality factors and wavelength-scale mode volumes, thus providing enhanced coupling between nanoscale quantum emitters and nanophotonic circuits. Realizing such resonant structures is particularly challenging for the visible wavelength …
We present a design methodology and analysis of a cavity optomechanical system in which a localized GHz frequency mechanical mode of a nanobeam resonator is evanescently coupled to a high quality factor (Q>10^6) optical mode of a separate nanobeam optical cavity. Using separate nanobeams provides flexibility, enabling the independent design and optimization of the optics and mechanics of the system. In addition, the small gap (approx. 25 nm) between the two resonators gives rise to a slot mode effect that enables a large zero-point optomechanical coupling strength to be achieved, with g/2pi > …
We demonstrate second harmonic generation at telecommunications wavelengths in L3 photonic crystal cavities in (111)-oriented GaAs. The second harmonic power from photonic crystal cavities fabricated in (111)-oriented GaAs is significantly increased compared to those fabricated in conventional (001)-oriented GaAs.
We demonstrate a simple and rapid epoxy-based method for transferring photonic crystal cavities to the facets of optical fibers. Passive Si cavities were measured via fiber taper coupling as well as direct transmission from the fiber facet. Active quantum dot containing GaAs cavities showed photoluminescence that was collected both in free space and back through the original fiber. Cavities maintain a high quality factor (2000-4000) in both material systems. This new design architecture provides a practical mechanically stable platform for the integration of photonic crystal cavities with macr…
We demonstrate photonic crystal nanobeam cavities that support both TE- and TM-polarized modes, each with a Quality factor greater than one million and a mode volume on the order of the cubic wavelength. We show that these orthogonally polarized modes have a tunable frequency separation and a high nonlinear spatial overlap. We expect these cavities to have a variety of applications in resonance-enhanced nonlinear optics.
We propose and experimentally demonstrate a photonic crystal nanocavity with multiple resonances that can be tuned nearly independently. The design is composed of two orthogonal intersecting nanobeam cavities. Experimentally, we measure cavity quality factors of 6,600 and 1000 for resonances separated by 382 nm; we measure a maximum separation between resonances of 506 nm. These structures are promising for enhancing efficiency in nonlinear optical processes such as sum/difference frequency and stimulated Raman scattering.
We propose and analyze a new type of a resonant high-Q cavity for lasing, sensing or filtering applications, which is based on a surface states of a finite photonic crystal. We demonstrate that such the cavity can have a Q factor comparable with that one of conventional photonic band-gap defect mode cavities. At the same time, the distinguished feature of the surface mode cavity is that it is situated directly at the surface of the photonic crystal. This might open up new possibilities for design of novel photonic devices and integration of photonic circuits.
One dimensional nano-beam photonic crystal cavities fabricated in silicon dioxide are considered in both simulation and experiment. Quality factors of over 10^4 are found via simulation, while quality factors of over 5*10^3 are found in experiment, for cavities with mode volumes of 2.0 cubic wavelengths (in oxide) and in the visible wavelength range (600-716nm). The dependences of the cavity quality factor and mode volume for different design parameters are also considered.
