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It has been shown that in the asymptotic case of infinite-key length, the 2-decoy state Quantum Key Distribution (QKD) protocol outperforms the 1-decoy state protocol. Here, we present a finite-key analysis of the 1-decoy method. Interestingly, we find that for practical block sizes of up to 108 bits, the 1-decoy protocol achieves for almost all experimental settings higher secret key rates than the 2-decoy protocol. Since using only one decoy is also easier to implement, we conclude that it is the best choice for QKD, in most common practical scenarios. [ABSTRACT FROM AUTHOR]

Quantum-based technologies have been instrumental in the development of a whole range of devices that are used these days (such as lasers, transistors, LiDAR, GPS, MRI, and many more). These technologies that emanated from the Quantum 1.0 Revolution have become ubiquitous in modern civilization over the past 50 years. The product commercialization and mass production were enabled by scientists, researchers, engineers, and most importantly, by the skilled technological workforce. This workforce played a critical support role in transforming inventions into high-volume, marketable products. We are currently at the heart of the Second Quantum Revolution, which is fueled by the research in quantum computing, quantum communication, quantum cryptography, and quantum sensing. The scientific progress that is currently taking place in these areas is going to fundamentally change the way we sense the world around us, approach our security, and process critical information. Governments and private entities across the world have recognized the strategic importance of quantum research-enabled technologies and have invested a significant amount of money to support graduate programs and research institutions where scientists, engineers, and other professionals are earning advanced degrees and immediately being engaged in active Quantum 2.0 research. To the best of our knowledge, and despite considerable investment in quantum research, no active efforts or programs exist that would train a quantum technological workforce at the technician level to support Quantum 2.0. The quantum industry, on the other side, has clearly identified the need for highly skilled quantum technicians that are able to support the commercialization of the new products and inventions. The lack of a trained quantum technician workforce is a major shortcoming that may have a profound negative impact on the long-term prospects and sustainability of the emerging quantum industry. The EdQuantum project, funded through the National Science Foundation (NSF) Advanced Technological Education (ATE) program, is an effort to close this shortcoming and propose a well-defined curriculum through which the incumbent photonic and laser technicians in the United States will be upskilled with the new skills and competencies from quantum research-enabled technologies. This paper presents the results of the first phase of the EdQuantum project—the quantum industry survey. Over the last few months, we sought input from the quantum industry as to what skills and competencies should a future quantum technician possess to support its emerging needs. The results collected during the survey are presented in this paper along with their impact on the proposed educational curriculum. This paper also elaborates on the alignment of the proposed curriculum with a few ongoing initiatives in the skilled technical workforce education (such as NSB Vision 2030, Convergence Accelerators Initiative, and Skilled Technical Workforce Initiative). [ABSTRACT FROM AUTHOR]

RGB (red-green-blue) technique for mapping skin chromophores by smartphones is proposed and studied. Three smartphones of different manufacturers were tested on skin phantoms and in vivo on benign skin lesions using a specially designed light source for illumination. Hemoglobin and melanin indices obtained by these smartphones showed differences in both tests. In vitro tests showed an increment of hemoglobin and melanin indices with the concentration of chromophores in phantoms. In vivo tests indicated higher hemoglobin index in hemangiomas than in nevi and healthy skin, and nevi showed higher melanin index compared to the healthy skin. Smartphones that allow switching off the automatic camera settings provided useful data, while those with "embedded" automatic settings appear to be useless for distant skin chromophore mapping. [ABSTRACT FROM AUTHOR]

The article presents examples of optical biomimetics from which optics practitioners may learn old solutions for new applications. It notes that colors of living creatures are produced by arrays of photonic elements. It explains two mechanisms that biological systems use to achieve color effects, namely pigment coloration that employs chemistry, and structural coloration that employs physics. Topics include structural coloration produced by light reflection, antireflection, and cell culture.

Analysing patent information is considered to be one of the most systematic and logical methodology to get an insight into the progress of technologies. Patent statistics can be used to ascertain the maturity of specific technologies or to identify technological trends. Similarly, it is possible to identify whether research activities are clustered or scattered by comparing the number of applications with the number of applicants. Visualization technique is considered to be most eloquent and illustrative way of representing patent information and its analysis results to get insight into various aspects of any particular technology. Statistical analysis of the relevant patent dataset is carried out using patent maps in the visualisation techniques. Different patent maps help in understanding various aspects about the searched system/ technology like top patent assignees, top Inventors. Time based analysis provides the trends of technology on the time scale, while cross-mapping of the patent documents provides further useful information. All the above analysis can be illustrated in patent maps to make it more presentable, structured and customised. In the present paper, the patent maps have been exploited to understand technologies and other aspects related to the Integrated Silicon Photonics. [ABSTRACT FROM AUTHOR]

An easy to realize L3 photonic crystal nanocavity that exhibits ultrahigh quality factor (Q-factor), ultrasmall mode volume, and a large Q/Vmode is proposed. A resonant cavity mode at 910.625 nm wavelength with Q-factor 4.93 x 105, mode volume 0.802 (λ/n)³, and Q/Vmode6.15 x 105 (λ/n)-3 is reported. The proposed design improves Q-factor by a factor of 84 and Q/Vmode by a factor of 70 in comparison to unoptimized L3 photonic crystal nanocavity. Such a high-quality nanocavity can be used to realize a strongly interacting quantum dot-nanocavity coupled system. [ABSTRACT FROM AUTHOR]

This work demonstrates the use of adaptive polymer lenses (APLs) for short-wavelength infrared (SWIR) applications. First, we present a push-button adaptive optical zoom system for variable magnification with a SWIR focal plane array. We then present a push-button, variable divergence, SWIR laser system for pointing and illumination. Last, we outline a system that combines the two: an SWIR adaptive zoom coupled with an APL-enhanced designator/illuminator. The result would allow a user to toggle between different fields of view (magnification), while optimizing illumination (beam divergence) for each field of view. This could be critical for situational awareness and target identification/designation in tactical applications. [ABSTRACT FROM AUTHOR]

Quantum superposition is the quantum-mechanical property of a particle whereby it inhabits several of its possible quantum states simultaneously. Ideally, this permissible coexistence of quantum states, as defined on any degree of freedom, whether spin, frequency or spatial, can be used to fully exploit the information capacity of the associated physical system. In quantum optics, single photons are the quanta of light, and their coherence properties allow them to establish entangled superpositions between a large number of channels, making them favourable for realizations of quantum information processing schemes. In particular, single-photon W-states (that is, states exhibiting a uniform distribution of the photons across multiple modes) represent a class of multipartite maximally-entangled quantum states that are highly robust to dissipation. Here, we report on the generation and verification of single-photon W-states involving up to 16 spatial modes, and exploit their underlying multi-mode superposition for the on-chip generation of genuine random numbers. [ABSTRACT FROM AUTHOR]

Siliconmicrocavity-based optical trapping of Au nanoparticleswith diameters as small as ≈24 nm is achieved using opticalpowers <1 mW. By comparing measured and modeled histograms of transmissiontime series data obtained when a particle is trapped in the cavity,it is shown that the influence of backaction on the transmitted lightdynamics alone can be used to determine the size of trapped particleswith nanometer precision. [ABSTRACT FROM AUTHOR]

In this paper, we will review research done by the Large-Scale Integrated Photonics group at HP Laboratories, and in particular we will discuss applications of optical resonances in dielectric microstructures and nanostructures to future classical and quantum information technologies. Our goal is to scale photonic technologies over the next decade in much the same way as electronics over the past five, thereby establishing a Moore's Law for optics. [ABSTRACT FROM AUTHOR]

The optical transfer functions of underwater imaging systems that use narrow beams modulated by a complex high-frequency signal to form an image are studied. Images of simple objects observed with the use of such systems are calculated. The image distortions caused by the interference of modulation waves are estimated, and a method for eliminating these distortions is proposed. The potential for improving the image quality through the application of complexly modulated illumination beams is demonstrated using explicit calculations. [ABSTRACT FROM AUTHOR]

A mid-IR amplifier consisting of a tapered chalcogenide fiber coupled to an Er3+-doped chalcogenide microsphere has been optimized via a particle swarm optimization (PSO) approach. More precisely, a dedicated three-dimensional numerical model, based on the coupled mode theory and solving the rate equations, has been integrated with the PSO procedure. The rate equations have included the main transitions among the erbium energy levels, the amplified spontaneous emission, and the most important secondary transitions pertaining to the ion-ion interactions. The PSO has allowed the optimal choice of the microsphere and fiber radius, taper angle, and fiber-microsphere gap in order to maximize the amplifier gain. The taper angle and the fiber-microsphere gap have been optimized to efficiently inject into the microsphere both the pump and the signal beams and to improve their spatial overlapping with the rare-earth-doped region. The employment of the PSO approach shows different attractive features, especially when many parameters have to be optimized. The numerical results demonstrate the effectiveness of the proposed approach for the design of amplifying systems. The PSO-based optimization approach has allowed the design of a microsphere-based amplifying system more efficient than a similar device designed by using a deterministic optimization method. In fact, the amplifier designed via the PSO exhibits a simulated gain G = 33.7 dB, which is higher than the gain G = 6.9 dB of the amplifier designed via the deterministic method. [ABSTRACT FROM AUTHOR]

We present the design, simulation, evaluation, and technological verification of various low-index optical demultiplexers based on arrayed waveguide gratings (AWGs). When designing such optical demultiplexers, a set of input geometrical parameters must be first calculated. They are essential to create AWG layout that will be then simulated using commercial photonics tools. However, these tools do not support or support only partially such a fundamental calculation. Therefore, a new stand-alone tool called AWG-Parameters was developed, which strongly reduces the time needed for the design. From the calculated geometrical parameters, the AWG layouts were created and simulated using three commercial photonic tools: Optiwave, (Ottawa, Ontario, Canada), Apollo Photonics, (Ancaster, Ontario, Canada), and R-Soft, (Pasadena, California). The designs were also technologically verified. The simulated/measured transmission characteristics were evaluated by our newly developed AWG-Analyzer tool. This tool provides calculations of AWG transmission parameters, which are also missing in commercial photonic tools. Additionally, the tool provides clear definitions of calculated transmission parameters together with their textual and graphical representations. Finally, the transmission characteristics and parameters achieved from different photonic tools were compared with each other and discussed in detail. The simulated results were also compared with the measurements. Very good agreement was achieved between theoretical (AWG-Parameters tool), simulated (commercial photonic tools), and fabricated AWG transmission parameters. [ABSTRACT FROM AUTHOR]

To meet energy-efficient performance demands, the computing industry has moved to parallel computer architectures, such as chip multiprocessors (CMPs), internally interconnected via networks-on-chip (NoC) to meet growing communication needs. Achieving scaling performance as core counts increase to the hundreds in future CMPs, however, will require high performance, yet energy-efficient interconnects. Silicon nanophotonics is a promising replacement for electronic on-chip interconnect due to its high bandwidth and low latency, however, prior techniques have required high static power for the laser and ring thermal tuning. We propose a novel nano-photonic NoC (PNoC) architecture, LumiNOC, optimized for high performance and power-efficiency. This paper makes three primary contributions: a novel, nanophotonic architecture which partitions the network into subnets for better efficiency; a purely photonic, in-band, distributed arbitration scheme; and a channel sharing arrangement utilizing the same waveguides and wavelengths for arbitration as data transmission. In a 64-node NoC under synthetic traffic, LumiNOC enjoys 50% lower latency at low loads and \sim40\% higher throughput per Watt on synthetic traffic, versus other reported PNoCs. LumiNOC reduces latencies \sim40\% versus an electrical 2-D mesh NoCs on the PARSEC shared-memory, multithreaded benchmark suite. [ABSTRACT FROM PUBLISHER]

Increasing scope and applications of integrated optics necessitates the development of automated techniques for physical design of optical systems. A key area of integrated optic design is waveguide routing, which currently lacks the level of automation found in VLSI design. Unlike VLSI, where signal nets are routed with metal layers and vias, integrated optics is a planar technology and lacks the inherent signal restoration capabilities of static-CMOS. Waveguides suffer signal loss due to planar (perpendicular) waveguide crossings and also from sharp bends. Therefore, in contrast to area or wire length, signal loss minimization—as a function of waveguide crossings and bends—is a primary objective of any routing solution. Our studies show that waveguide routing problems can be suitably formulated as planar channel routing. This paper investigates channel routing for integrated optical waveguides fabricated in a planar substrate. We present routing techniques where crossings, bends, and area are accounted for in an integrated solution. Two distinct channel routing techniques are presented: 1) a new channel router based on net sorting and utilizing non-Manhattan routing grids and 2) a router based on crossing-aware graph-constrained track assignment that also exploits waveguide curves to improve track utilization. Both techniques are crossing-minimal, and are also constrained suitably to reduce bend loss and area. We compare and evaluate the performance of our channel routers on a number of optical design benchmarks. [ABSTRACT FROM PUBLISHER]

The main purpose of this study is to establish radiation-safe scanning of passersby at high security areas, such as airports and customs. The stomach was selected as the organ to be analyzed. In order to determine whether a substance found inside a human body as wrapped in a plastic bag is filled narcotics or not, many substances in white powder form including morphine-HCL were inspected. Inspection was carried out with on-ionizing radiation by irradiating stomach tissue with laser light. Optical transmittance of lamb stomach tissue was analyzed at different wavelengths. We showed that detection by 650-nm diode laser irradiation would be suitable for such a radiation-safe scan. Different materials were also investigated for absorptive properties, and closed system Raman studies were performed. The spectrum of a molecule found inside white powder placed behind the lamb stomach tissue was detected as a fingerprint. This allowed the detection of target substances without any physical contact or damage to the biological tissu [ABSTRACT FROM AUTHOR]

The article presents news briefs related to the optics and photonics industry. The German micro- and nanotechnology industry has shown a significant improvement in the year 2013. The German machine vision industry is moving on a stable growth path. Toptica Photonics AG has developed a new generation of sodium guide star lasers for deployment at ESO's Very Large Telescope VLT in Paranal, Chile.

Ultrahigh-quality (Q) factor microresonators have a lot of applications in the photonics domain ranging from low-threshold nonlinear optics to integrated optical sensors. Glass-based whispering gallery mode (WGM) microresonators are easy to produce by melting techniques, however they suffer from surface contamination which limits their long-term quality factor to a few 108. Here we show that an optical gain provided by erbium ions can compensate for residual losses. Moreover it is possible to control the coupling regime of an ultrahigh Q-factor three port microresonator from undercoupling to spectral selective amplification by changing the pumping rate. The optical characterization method is based on frequency-swept cavity-ring-down-spectroscopy. This method allows the transmission and dispersive properties of perfectly transparent microresonators and intrinsic finesses up to 4.0 × 107 to be measured. Finally we characterize a critically coupled fluoride glass WGM microresonator with a diameter of 220 mm and a loaded Q-factor of 5.3 × 109 is demonstrated. [ABSTRACT FROM AUTHOR]

The table of contents for the January 2014 issue of "Laser & Photonics Reviews" is presented.

Abstract: The paper proposes the metal–insulator–metal (MIM) waveguides with different tooth-shapes (rectangle-tooth and triangle-tooth) and calculates the corresponding power spectrums by discrete Fourier transform. The finite difference time domain (FDTD) simulation results show that the spectrum transformations reveal the significant differences in the two structures with the same tooth-depth, such as amplitudes, amplitudes difference and spacing of the two peaks. The study will be useful in waveform modulation in the communication wavelength. Furthermore, the spectrum may also be used to detect different nanostructures based on the corresponding transformations. [Copyright &y& Elsevier]

A compact crossing scheme for a silicon-based slot-to-strip (or vice versa) waveguide is proposed and analyzed by using a finite-difference time-domain method, where a strip–multimode waveguide (SMW) crossing is used at the center and two logarithmically tapered slot-to-strip mode converters are incorporated into the ports with slot waveguides. For the input ports with slot waveguides and output ports with strip waveguides, the guided modes are efficiently transformed through the mode converter, and then enter into the SMW, where the fields converge at the center of the intersection due to the self-imaging effect. Hence, the size of the input beam is much smaller than the width of the SMW at the crossing center, leading to significant reductions of both crosstalk and radiation loss. The numerical results show that a slot-to-strip waveguide crossing operating at a wavelength of 1.55??m can be achieved with insertion loss, crosstalk, and reflection of 0.134/0.182, ?36.18/?38.6, and ?35.8/?42.02?dB for input ports with slot/strip waveguides, respectively. [ABSTRACT FROM PUBLISHER]

A numerical study is reported of the propagation of an initially localized wave in a one-dimensional disordered lattice composed of left-handed metamaterials. We first consider the structure made of right-handed and left-handed materials arranged periodically. By allowing disorder in the refractive index of the right-handed materials, the injected wave becomes localized as propagating through the disordered lattice. Then, we consider another photonic lattice comprising only left-handed metamaterials. It is found that the inclusion of disorder in the negative refractive index of the constituents of the system leads to transverse Anderson localization. We also investigate the dispersion effect of metamaterials on the localization behavior. It is demonstrated that inclusion of a dispersive metamaterial in the disordered photonic lattices causes the quality of transverse localization to enhance with increasing wavelength. [ABSTRACT FROM PUBLISHER]

Abstract: This paper seeks to investigate an approach of photonic reservoir computing for optical speech recognition on an examination isolated digit recognition task. An analytical approach in photonic reservoir computing is further drawn on to decrease time consumption, compared to numerical methods; which is very important in processing large signals such as speech recognition. It is also observed that adjusting reservoir parameters along with a good nonlinear mapping of the input signal into the reservoir, analytical approach, would boost recognition accuracy performance. Perfect recognition accuracy (i.e. 100%) can be achieved for noiseless speech signals. For noisy signals with 0–10db of signal to noise ratios, however, the accuracy ranges observed varied between 92% and 98%. In fact, photonic reservoir application demonstrated 9–18% improvement compared to classical reservoir networks with hyperbolic tangent nodes. [Copyright &y& Elsevier]

A small, portable, high-flux correlated photon-pair source has been designed and constructed from simple opto-mechanical parts. Unique to this device is its straightforward alignment process, together with the direct coupling of signal and idler photons into polarization-maintaining single-mode optical fibers. Spontaneous parametric down-conversion is used to produce photon pairs in β-barium borate (BBO) at a center wavelength of 810 nm. Owing to the applied type-I phase-matching, coincident photons have identical polarization. The estimated fiber-coupling efficiency is 51%, the measured photon and coincidence flux are 636 and 130 kHz/mW, respectively, normalized to pump power (44 mW). The source has an extremely wide wavelength spectrum of 202-nm FWHM, measured at the fiber output, which limits the actual heralding ratio to 20%. [ABSTRACT FROM AUTHOR]

Aero-optical beam control relies on the development of low-latency forecasting techniques to quickly predict wavefronts aberrated by the turbulent boundary layer around an airborne optical system, and its study applies to a multidomain need from astronomy to microscopy for high-fidelity laser propagation. We leverage the forecasting capabilities of the dynamic mode decomposition (DMD) — an equation-free, data-driven method for identifying coherent flow structures and their associated spatiotemporal dynamics — to estimate future state wavefront phase aberrations to feed into an adaptive optic control loop. We specifically leverage the optimized DMD (opt-DMD) algorithm on a subset of the Airborne Aero-Optics Laboratory-Transonic experimental dataset, characterizing aberrated wavefront dynamics for 23 beam propagation directions via the spatiotemporal decomposition underlying DMD. Critically, we show that opt-DMD produces an optimally debiased eigenvalue spectrum with imaginary eigenvalues, allowing for arbitrarily long forecasting to produce a robust future state prediction, while exact DMD loses structural information due to modal decay rates. [ABSTRACT FROM AUTHOR]

A metalens is a planar optical device that can accurately control the phase, polarization, and amplitude of light. Aiming at the application requirements of polarization imaging equipment for miniaturization, integration, and common field of view, we designed and fabricated two kinds of orthogonally polarized metalenses based on amorphous silicon and fused quartz. These metalenses can achieve orthogonal linear or circular polarization light imaging with a common field of view. The samples with a 2-mm diameter and 20-mm focal length were fabricated by electron beam exposure. The test results show that these metalenses can realize the imaging of orthogonal linearly or circularly polarized light simultaneously; the focusing efficiency is more than 50%, and the polarization contrast is >22 dB. [ABSTRACT FROM AUTHOR]