Nanowerk December 15, 2023 Negatively charged group-IV color centers in diamond are promising candidates for quantum memories as they combine long storage times with excellent optical emission properties and an optically addressable spin state. However, as a material, diamond lacks the many functionalities needed to realize scalable quantum systems. Thin-film lithium niobate (TFLN), in contrast, offers several useful photonic nonlinearities, including the electro-optic effect, piezoelectricity, and capabilities for periodically poled quasi-phase matching. Researchers at Stanford University have presented highly efficient heterogeneous integration of diamond nanobeams containing negatively charged silicon-vacancy (SiV) centers with TFLN waveguides. They observed greater than 90% transmission […]
Tag Archives: Quantum photonics
New metalens lights the way for advanced control of quantum emission
Phys.org August 8, 2023 Traditional control of emission from quantum light sources relies on the use of multiple bulky optical elements or nanostructured resonators with limited functionalities, constraining the potential of multi-dimensional tailoring. An international team of researchers (Australia, South Korea) designed an ultrathin polarisation-beam-splitting metalens for the arbitrary structuring of quantum emission at room temperature. Due to the complete and independent polarisation and phase control at the single meta-atom level, the metalens enabled simultaneous mapping of quantum emission from ultra-bright defects in hexagonal boron nitride and imprinting of an arbitrary wavefront onto orthogonal polarisation states of the sources. The […]
Researchers devise new quantum photonics technique to create better holograms
Phys.org July 10, 2023 It is possible to observe interference between independent light sources by measuring correlations in their intensities rather than their amplitudes. An international team of researchers (Canada, UK) applied this concept of intensity interferometry to holography. They combined a signal beam with a reference and measured their intensity cross-correlations using a time-tagging single-photon camera. The correlations revealed an interference pattern from which they reconstructed the signal wavefront in both intensity and phase. They demonstrated the principle with classical and quantum light, including a single photon. Since the signal and reference do not need to be phase-stable nor […]
A new method to enable efficient interactions between photons
Phys.org October 6, 2022 Photonics stands out as fundamental to realize the full potential of quantum technology. It provides a modular approach where the main challenges lie in the construction of high-quality building blocks and in the development of methods to interface the modules. In a review article an international team of researchers (France, UK, Canada, Germany, Denmark, South Korea) used the example of quantum dot devices to present the physics of deterministic photon–emitter interfaces, including the main photonic building blocks required to scale up, and discuss quantitative performance benchmarks. While their focus is on quantum dot devices, the presented […]
Heat-free optical switch would enable optical quantum computing chips
Nanowerk March 3, 2021 In quantum integrated photonics integrated detectors offer optical readout and when interfaced with reconfigurable circuits, allow feedback and adaptive control, crucial for deterministic quantum teleportation, training of neural networks, and stabilization of complex circuits. However, the heat generated by thermally reconfigurable photonics is incompatible with heat-sensitive superconducting single-photon detectors, and thus their on-chip co-integration remains elusive. An international team of researchers (Sweden, Austria) has designed low-power microelectromechanical reconfiguration of integrated photonic circuits interfaced with superconducting single-photon detectors on the same chip. They demonstrated three key functionalities for photonic quantum technologies: 28 dB high-extinction routing of classical […]
Programming light on a chip
Eurekalert January 8, 2019 An international team of researchers (USA – Harvard University, Howard University, China) has demonstrated a ‘photonic molecule’ with two distinct energy levels using coupled lithium niobate microring resonators and control it by external microwave excitation. They showed that the frequency and phase of light can be precisely controlled by programmed microwave signals and on-demand optical storage and retrieval by reconfiguring the photonic molecule into a bright–dark mode pair. These results open doors to applications in microwave signal processing, quantum photonic gates in the frequency domain and exploring concepts in optical computing and topological physics…read more. TECHNICAL […]