We fabricated an optical interferometric gyroscope front-end with a tunable laser on the heterogeneous silicon platform. We successfully demonstrated a laser based gyroscope with low noise floor comparable to a commercial ASE based gyroscope.
In this paper, two different methods of polarization diverse recovery of the modulation are described in a novel coherent receiver architecture employing four coherent detectors that re-establishes the symmetry between random time-varying signal and reference.
Exciton-polaritons are bosonic quasi-particles originating in the strong coupling regime. They can undergo a condensation process leading to coherent emission. We show a realisation of electrically driven polariton condensates using a p-i-n doped microcavity.
A novel design approach for photonic Hilbert transformers based on their specifications in time domain is presented. Simulation results reveal a significant simplification in the fabrication process when implemented as fiber or waveguide Bragg gratings.
We present different architectures of mode-locked lasers based on semiconductor devices for different applications of interest for microwave photonics like high frequency signal generation, low phase noise oscillators or high speed analogue signal sampling. For these applications we demonstrate both monolithic Fabry-Perot cavities and also external cavities using semiconductor optical amplifiers. Emission wavelength are for most of demonstrations at 1.5 μm but there are also demonstrations at 0.8 μm of interest for high speed sampling when associated with low temperature grown gallium arsenide photoswitches.
We study four different measurement methods of multi-path interference (MPI) in quasi-single-mode (QSM) fibers and compare their consistency and accuracy. Three methods agree to within 1.7 dB in each case while one overestimates MPI.
Silicon-On-Insulator and Germanium-On-Insulator are both promising waveguide platforms for the mid-infrared wavelength of 2 μm. Here, we report the design of passive and active devices including multimode interference couplers (MMI) and MZI modulators built on both platforms.
We will discuss the recent progresses of the Fourier ptychographic imaging approach. We will demonstrate its applications in gigapixel microscopy, quantitative phase imaging, spectrum multiplexing, 3D holographic imaging, structured illumination microscopy, super-resolution fluorescence microscopy, and photographic imaging.
A 703 fs cavity-less pulse source based on pulse carving and pulse compression is demonstrated and utilized for demultiplexing a 640 Gbaud OTDM signal. Timing jitter is found to be the main limiting factor.
Single photons are efficiently collected based on a tunable microfiber-coupled photonic crystal cavity with an embedded InAs quantum dot. 25% of total fiber collection efficiency is obtained. Tunability of the cavity and Purcell-enhanced spontaneous emission rate are also observed.
Electron transfer is a fundamental process in biochemistry, which triggers a number of biochemical processes such as photosynthesis, cellular respiration and electron transport along DNA [1]. It has been recognized that the evolution of many biological processes is strictly related to the ultrafast time scale of the corresponding electron dynamics. With the advent of attosecond technology, it was proposed to track and control this electron dynamics in real time. Indeed, the electron dynamics occurring in a biomolecule after sudden ionization can be driven by purely electronic effects and charge migration (CM) from one end of the molecule to the other and back has been theoretically predicted to occur within a time scale ranging from few-femtoseconds down to hundreds-attoseconds [2].
Summary form only given. Large-scale quantum networks will require efficient interfaces between photons and stationary quantum bits. Nitrogen vacancy (NV) centers in diamond are a promising candidate for quantum information processing because they are optically addressable, have spin degrees of freedom with long coherence times, and as solid-state entities, can be integrated into nanophotonic devices. An enabling feature of the NV center is its zero-phonon line (ZPL), which acts as an atom-like cycling transition that can be used for coherent optical manipulation and read-out of the spin. However, the ZPL only accounts for 3-5% of the total emission, and previously demonstrated methods of producing high densities of NV centers yield unstable ZPLs. I will present methods and technologies for gaining both spectral and spatial control over NV emission by coupling NV centers to nanophotonic devices. In particular, we have developed a method to create a high-density device layer of NVs with stable ZPLs in high purity diamond, and have devised a fabrication scheme to carve single mode waveguides out of the surface of the bulk diamond substrate. Using this technique, we are able to fabricate high quality factor, small mode volume photonic crystal cavities directly out of diamond, and deterministically position these photonic crystal cavities so that a stable NV center sits at the maximum electric field. We observe an enhancement of the spontaneous emission at the cavity resonance by a factor of up to 100. The NV emission is guided efficiently into a single optical mode, enabling integration with other photonic elements, as well as networks of cavities, each with their own optically addressable qubit. These nanophotonic elements in diamond will provide key building blocks for quantum information processing such as single photon transistors, enabling distribution of entanglement over quantum networks.
We demonstrated an InAsP/InP nanowire laser (diameter ~100 nm) in telecommunication band on an Si photonic crystal platform. By measuring light-in versus light-out curves, linewidth, emission rate, and photon correlation, lasing oscillation has been unambiguously demonstrated.
An artificially-engineered InGaN-based digital alloy is investigated based on GaN/InN superlattice, and the findings indicate the capability of this material system to achieve tunable bandgap and absorption properties for optoelectronic applications.
We have developed a technological platform that can be used for remote sensing of nano-vibrations which can be used for biomedical parameters estimation as well as for establishing a directional communication channel. The technology is based upon illuminating a surface with a laser and then using an imaging camera to perform temporal and spatial tracking of secondary speckle patterns in order to have nano metric accurate estimation of the movement of the back reflecting surface. If the back reflecting surface is a skin located close to main blood arteries then biomedical monitoring can be realized. If the surface is close to our neck or head then a directional communication channel can be established for remote, directional and noise isolated sensing of speech signals. The proposed technology was already applied for remote and continuous estimation of heart beats, respiration, blood pulse pressure, intra-ocular pressure (IOP), estimation of alcohol and glucose concentrations in blood stream, blood coagulation and oximetry.
Diode laser bars with optimized epitaxial designs, long resonators and passivated facets deliver joule-class millisecond pulses (kilowatts of peak power) with the properties needed by advanced high-energy-class solid-state laser systems, at brightness over 3 MW/(cm(2)sr).
We produced a 3-15-ns CO 2 laser pulse with 10 11 W/cm 2 for an efficient extreme ultraviolet (EUV) source by rare earth element of Gd. The EUV emission was observed a sharp spectral structure at 6.79 nm.
We report the first integrated refractometric sensor capable of detecting atmospheric CO 2 gas concentration levels. The sensor employs a microring resonator functionalized with a guanidine polymer and can detect CO 2 concentrations down to 250ppm with a 25ppm resolution.
A tunable bottle microresonator can trap an optical pulse of the given spectral width, hold it as long as the material losses permit, and release without distortion.
A high average power ultrafast short-IR OPCPA system was realized. Operated at up to 100kHz pulse repetition frequency, record average powers of 6W and 7.5W were generated for few-cycle to 10s femtoseconds pulses at 2μm and 1.5μm carrier wavelengths, respectively. Implications of thermal effects and nonlinearities are discussed. The study paves the way towards multi-10 Watt few-cycle OPCPA systems at 2μm, e.g. for high field physics applications.
