A cost-effective ADC system with seven distinct stretch factors is demonstrated using a photonic time-stretched analog-to-digital converter (PTS-ADC) based on a dispersion-tunable chirped fiber Bragg grating (CFBG). To achieve a range of sampling points, the stretch factors are adaptable by altering the dispersion of CFBG. Consequently, the system's overall sampling rate can be enhanced. The effect of multi-channel sampling can be realized by increasing the sampling rate via a single channel. In conclusion, seven categories of stretch factors, varying from 1882 to 2206, are generated, mirroring seven unique clusters of sampling points. The input radio frequency (RF) signals within the 2 GHz to 10 GHz spectrum were successfully retrieved. Enhancing the equivalent sampling rate to 288 GSa/s is achieved by increasing the sampling points by a factor of 144. The proposed scheme is compatible with commercial microwave radar systems, which can attain a greatly increased sampling rate at a minimal cost.
Recent improvements in ultrafast, large-modulation photonic materials have dramatically widened the horizons of research. Vanzacaftor solubility dmso A striking demonstration is the exhilarating possibility of photonic time crystals. This overview presents the most recent breakthroughs in materials science that may contribute to the development of photonic time crystals. We scrutinize the worth of their modulation in relation to its speed and depth of adjustment. In addition, we explore the challenges that remain, and furnish our projections for prospective paths to victory.
The significance of multipartite Einstein-Podolsky-Rosen (EPR) steering as a resource in quantum networks cannot be overstated. Though EPR steering has been observed in spatially separated ultracold atomic systems, a secure quantum communication network critically requires deterministic control over steering between distant quantum network nodes. Employing a cavity-enhanced quantum memory, this paper details a workable technique for the deterministic creation, storage, and management of one-way EPR steering between distinct atomic units. Faithfully storing three spatially separated entangled optical modes within three atomic cells creates a strong Greenberger-Horne-Zeilinger state, which optical cavities effectively use to suppress the unavoidable electromagnetic noises in electromagnetically induced transparency. Thanks to the profound quantum correlation within the atomic cells, one-to-two node EPR steering is achieved, and the stored EPR steering is consequently preserved within these quantum nodes. The steerability of the system is further modulated by the atomic cell's temperature. Experimental implementation of one-way multipartite steerable states is directly guided by this scheme, enabling a functional asymmetric quantum network protocol.
We probed the optomechanical dynamics and quantum phase transitions of Bose-Einstein condensates constrained to a ring cavity. A semi-quantized spin-orbit coupling (SOC) is a consequence of the interaction of atoms with the running wave mode of the cavity field. Regarding the matter field's magnetic excitations, their evolution shows remarkable similarity to an optomechanical oscillator traversing a viscous optical medium, maintaining excellent integrability and traceability across all atomic interactions. Consequently, the link between light atoms produces a sign-alternating long-range atomic interaction, substantially transforming the system's conventional energy pattern. The transitional area for SOC revealed a new quantum phase exhibiting high quantum degeneracy. Our scheme's immediate realizability translates to measurable results that are verifiable through experiments.
A novel interferometric fiber optic parametric amplifier (FOPA) is presented, which, to our understanding, is the first of its kind, eliminating unwanted four-wave mixing products. Our simulations investigate two arrangements; the first rejects idler signals, and the second rejects non-linear crosstalk at the signal output port. The simulations presented numerically demonstrate the practical applicability of suppressing idlers by greater than 28 decibels over a range of at least 10 terahertz, allowing for the reuse of idler frequencies for signal amplification and thus doubling the employable FOPA gain bandwidth. The accomplishment of this goal, even with real-world couplers in the interferometer, is illustrated by the addition of a small amount of attenuation in one arm of the interferometer.
Coherent beam combining of 61 tiled channels from a femtosecond digital laser is employed to control the far-field energy distribution. Independent control of amplitude and phase is implemented for each channel, considered a pixel. Establishing a phase shift between neighboring fibers or fiber arrangements grants greater agility to the distribution of energy in the far field, propelling further investigation into phase patterns as a means to potentially optimize tiled-aperture CBC laser efficiency and dynamically shape the far field.
Two broadband pulses, a signal and an idler, are a result of optical parametric chirped-pulse amplification, and both are capable of generating peak powers higher than 100 GW. In the majority of instances, the signal is applied, yet compressing the idler with a longer wavelength yields opportunities for experiments in which the driving laser wavelength takes on significant importance. The petawatt-class, Multi-Terawatt optical parametric amplifier line (MTW-OPAL) at the Laboratory for Laser Energetics required the addition of new subsystems, as detailed in this paper, to address problems associated with the idler, angular dispersion, and spectral phase reversal. Within the scope of our knowledge, this constitutes the first achievement of simultaneous compensation for angular dispersion and phase reversal within a single system, generating a 100 GW, 120-fs pulse duration at 1170 nm.
The efficacy of electrodes directly impacts the progress of smart fabric technology. Common fabric flexible electrodes' preparation often suffers from the drawbacks of expensive materials, intricate preparation methods, and complex patterning, thereby impeding the wider adoption of fabric-based metal electrodes. This paper demonstrated a facile fabrication technique for copper electrodes by means of selective laser reduction of copper oxide nanoparticles. By strategically adjusting laser processing parameters, namely power, scan rate, and focus, a copper circuit possessing an electrical resistivity of 553 micro-ohms per centimeter was constructed. Capitalizing on the photothermoelectric properties of the copper electrodes, a white light photodetector was developed. At a power density of 1001 milliwatts per square centimeter, the photodetector's detectivity achieves a value of 214 milliamperes per watt. Fabric surface metal electrode or conductive line preparation is facilitated by this method, enabling the creation of wearable photodetectors with specific manufacturing techniques.
A computational manufacturing program for monitoring group delay dispersion (GDD) is presented. GDD's computationally manufactured broadband and time-monitoring simulator dispersive mirrors, two distinct types, are subjected to a comparative evaluation. Regarding dispersive mirror deposition simulations, the results emphasized the particular advantages of GDD monitoring. The subject of GDD monitoring's self-compensatory effect is addressed. Improved precision in layer termination techniques, facilitated by GDD monitoring, may well extend to the manufacture of other optical coatings.
We illustrate a method to gauge average temperature changes in operating optical fiber networks via Optical Time Domain Reflectometry (OTDR), at the resolution of a single photon. We formulate a model in this paper that links temperature changes in an optical fiber to corresponding shifts in the time of flight of reflected photons, spanning from -50°C to 400°C. The system configuration showcases temperature change measurements, precise to 0.008°C, over a kilometer-scale within a dark optical fiber network deployed throughout the Stockholm metropolitan region. By employing this approach, in-situ characterization becomes possible for both quantum and classical optical fiber networks.
Our report outlines the advancements in mid-term stability for a tabletop coherent population trapping (CPT) microcell atomic clock, which was previously constrained by light-shift effects and variations of the cell's interior atmospheric conditions. Employing a pulsed symmetric auto-balanced Ramsey (SABR) interrogation technique, along with temperature, laser power, and microwave power stabilization, the light-shift contribution is now minimized. Vanzacaftor solubility dmso By incorporating a micro-fabricated cell made from low-permeability aluminosilicate glass (ASG) windows, the cell's buffer gas pressure fluctuations have been considerably lessened. Vanzacaftor solubility dmso A combination of these techniques establishes the clock's Allan deviation at 14 x 10^-12 at 105 seconds. The level of stability achieved by this system within a single day compares favorably with the highest performing microwave microcell-based atomic clocks of today.
Within a photon-counting fiber Bragg grating (FBG) sensing system, a narrower probe pulse width leads to a sharper spatial resolution, but, consequentially, the Fourier transform-based spectrum broadening impairs the sensing system's sensitivity. A dual-wavelength differential detection method is employed in this investigation to examine the effect that spectrum broadening has on a photon-counting fiber Bragg grating sensing system. A theoretical model forms the basis for the proof-of-principle experimental demonstration realized. Our study reveals a numerical connection between the spatial resolution and sensitivity of FBG sensors across a range of spectral widths. A commercially manufactured FBG, possessing a spectral width of 0.6 nanometers, yielded a noteworthy spatial resolution of 3 millimeters in our experiment, coupled with a sensitivity of 203 nanometers per meter.