6 Search Results

Silicon vacancy centers (SiVs) in diamond have emerged as a promising platform for quantum sciences due to their excellent photostability, minimal spectral diffusion, and substantial zero-phonon line emission. However, enhancing their slow nanosecond excited-state lifetime by coupling to optical cavities remains an outstanding challenge, as current demonstrations are limited to ~10-fold. Here, we couple negatively charged SiVs to sub-diffraction-limited plasmonic cavities and achieve an instrument-limited ≤8 ps lifetime, corresponding to a 135-fold spontaneous emission rate enhancement and a 19-fold photoluminescence enhancement. Nanoparticles are printed on ultrathin diamond membranes on gold films which create arrays of plasmonic nanogap cavities with ultrasmallmore » volumes. SiVs implanted at 5 and 10 nm depths are examined to elucidate surface effects on their lifetime and brightness. The interplay between cavity, implantation depth, and ultrathin diamond membranes provides insights into generating ultrafast, bright SiV emission for next-generation diamond devices.« less

Phonons traveling in solid-state devices are emerging as a universal excitation for coupling different physical systems. Phonons at microwave frequencies have a similar wavelength to optical photons in solids, enabling optomechanical microwave-optical transduction of classical and quantum signals. It becomes conceivable to build optomechanical integrated circuits (OMIC) that guide both photons and phonons and interconnect photonic and phononic devices. Here, we demonstrate an OMIC including an optomechanical ring resonator (OMR), where co-resonant infrared photons and GHz phonons induce significantly enhanced interconversion. The platform is hybrid, using wide bandgap semiconductor gallium phosphide (GaP) for waveguiding and piezoelectric zinc oxide (ZnO) formore » phonon generation. The OMR features photonic and phononic quality factors of >1 × 10⁵ and 3.2 × 10³, respectively. The optomechanical interconversion between photonic modes achieved an internal conversion efficiency $$η_i$$ = (2.1 ± 0.1)% and a total device efficiency $$η_{tot}$$ = 0.57 x 10^-6 at a low acoustic pump power of 1.6 mW. The efficient conversion in OMICs enables microwave-optical transduction for quantum information and microwave photonics applications.« less

We demonstrate quasi-phase matched, triply-resonant sum frequency conversion in 10.6-µm-diameter integrated gallium phosphide ring resonators. A small-signal, waveguide-to-waveguide power conversion efficiency of 8 ± 1.1%/mW; is measured for conversion from telecom (1536 nm) and near infrared (1117 nm) to visible (647 nm) wavelengths with an absolute power conversion efficiency of 6.3 ± 0.6%; measured at saturation pump power. For the complementary difference frequency generation process, a single photon conversion efficiency of 7.2%/mW from visible to telecom is projected for resonators with optimized coupling. Efficient conversion from visible to telecom will facilitate long-distance transmission of spin-entangled photons from solid-state emitters such as the diamondmore » NV center, allowing long-distance entanglement for quantum networks.« less

The compact size, scalability, and strongly confined fields in integrated photonic devices enable new functionalities in photonic networking and information processing, both classical and quantum. Gallium phosphide (GaP) is a promising material for active integrated photonics due to its high refractive index, wide bandgap, strong nonlinear properties, and large acousto-optic figure of merit. Here, this study demonstrates that silicon-lattice-matched boron-doped GaP (BGaP), grown at the 12-inch wafer scale, provides similar functionalities as GaP. BGaP optical resonators exhibit intrinsic quality factors exceeding 25,000 and 200,000 at visible and telecom wavelengths, respectively. It further demonstrates the electromechanical generation of low-loss acoustic wavesmore » and an integrated acousto-optic (AO) modulator. High-resolution spatial and compositional mapping, combined with ab initio calculations, indicate two candidates for the excess optical loss in the visible band: the silicon-GaP interface and boron dimers. These results demonstrate the promise of the BGaP material platform for the development of scalable AO technologies at telecom and provide potential pathways toward higher performance at shorter wavelengths.« less

Optically addressable solid-state defects are emerging as some of the most promising qubit platforms for quantum networks. Maximizing photon-defect interaction by nanophotonic cavity coupling is key to network efficiency. We demonstrate fabrication of gallium phosphide 1-D photonic crystal waveguide cavities on a silicon oxide carrier and subsequent integration with implanted silicon-vacancy (SiV) centers in diamond using a stamp-transfer technique. The stamping process avoids diamond etching and allows fine-tuning of the cavities prior to integration. After transfer to diamond, we measure cavity quality factors (Q) of up to 8900 and perform resonant excitation of single SiV centers coupled to these cavities.more » For a cavity with a Q of 4100, we observe a 3-fold lifetime reduction on-resonance, corresponding to a maximum potential cooperativity of C = 2. In conclusion, these results indicate promise for high photon-defect interaction in a platform which avoids fabrication of the quantum defect host crystal.« less

We demonstrate post-fabrication target-wavelength trimming with a gallium phosphide on a silicon nitride integrated photonic platform using controlled electron-beam exposure of hydrogen silsesquioxane cladding. A linear relationship between the electron-beam exposure dose and resonant wavelength red-shift enables deterministic, individual trimming of multiple devices on the same chip to within 30 pm of a single target wavelength. Second harmonic generation from telecom to near infrared at a target wavelength is shown in multiple devices with quality factors on the order of 10 ⁴ . Post-fabrication tuning is an essential tool for targeted wavelength applications including quantum frequency conversion.