Optical Science Research Articles

Single-Photon Counting with Semiconductor Resonant Tunneling Devices.

Optical quantum information science and technologies require the capability to generate, control, and detect single or multiple quanta of light. The need to detect individual photons has motivated the development of a variety of novel and refined single-photon detectors (SPDs) with enhanced detector performance. Superconducting nanowire single-photon detectors (SNSPDs) and single-photon avalanche diodes (SPADs) are the top-performer in this field, but alternative promising and innovative devices are emerging. In this review article, we discuss the current state-of-the-art of one such alternative device capable of single-photon counting: the resonant tunneling diode (RTD) single-photon detector. Due to their peculiar photodetection mechanism and current-voltage characteristic with a region of negative differential conductance, RTD single-photon detectors provide, theoretically, several advantages over conventional SPDs, such as an inherently deadtime-free photon-number resolution at elevated temperatures, while offering low dark counts, a low timing jitter, and multiple photon detection modes. This review article brings together our previous studies and current experimental results. We focus on the current limitations of RTD-SPDs and provide detailed design and parameter variations to be potentially employed in next-generation RTD-SPD to improve the figure of merits of these alternative single-photon counting devices. The single-photon detection capability of RTDs without quantum dots is shown.

A survey on photonics technologies for radar applications

Photonics is a fast and galloping technology related to both microwave and optics science. Photonics is a very vast and distinctive field in recent days. Due to the enlarged difficulty of the electronics component for large bandwidth, we had to rely on the delightful photonics system. Photonics-based system came to us as a blessing in science research in this era. Software-defined photonics-based radar must be the near forthcoming next-generation necessities. This paper has a detailed study of photonics radar and how its components work. A comparative study has been presented with the traditional electronics microwave radar systems and photonics radar systems. The slow evolution of optics system and how the application has been pushed to radar, microwave and antenna systems have been described here. In this survey repost starting from the historical storyline and basics of photonics radar, the concept of radar based on photonics system and its need, then the digitized PhoDIR system invention, radio frequency signal generation and modulation, beamforming over antenna array and signal transportation, we have discussed the important architecture of photonics radar, phase control process, sampling process, transceiver modules till the radar parameter measurements and various applications of photonics radar including quantum radar. Photonics radar seemed to be a very intense and bright research study area; many practical problems and its wonderful solution have been described here. In this paper, the advancement and progression of photonics-based radar communication system accomplishments of the last decades has been shown and also discussions about future study and development of photonics radar have been presented.

Lab tests of segment/petal phasing with a pyramid wavefront sensor and a holographic dispersed fringe sensor in turbulence with the Giant Magellan Telescope high contrast adaptive optics phasing testbed

The Giant Magellan Telescope (GMT) design consists of seven circular 8.4-m diameter mirrors, together forming a single 25.4-m diameter primary mirror. This large aperture and collecting area can help extreme adaptive optics (ExAO) systems such as GMT’s GMagAO-X achieve the small angular resolutions and contrasts required to image habitable zone earth-like planets around late type stars and possibly lead to the discovery of life outside of our solar system. However, the GMT primary mirror segments are separated by large >30 cm gaps, creating the possibility of fluctuations in optical path differences (piston) due to flexure, segment vibrations, wind buffeting, temperature effects, and atmospheric seeing. To utilize the full diffraction-limited aperture of the GMT for high-contrast, natural guide star-adaptive optics science, the seven mirror segments must be co-phased to well within a fraction of a wavelength. The current design of the GMT involves seven adaptive secondary mirrors, a slow (∼0.03 Hz) off-axis dispersed fringe sensor (part of the acquisition guiding and wavefront sensing system’s active optics off-axis guider), and a pyramid wavefront sensor [PyWFS; part of the natural guide star wavefront sensor (NGWS) adaptive optics] to measure and correct the total path length between segment pairs, but these methods have yet to be tested “end-to-end” in a lab environment. We present the design and working prototype of a “GMT high contrast adaptive optics phasing testbed” that leverages the existing MagAO-X ExAO instrument to demonstrate segment phase sensing and simultaneous AO-control for high-contrast GMT natural guide star science [i.e., testing the NGWS wavefront sensor (WFS) architecture]. We present the first test results of closed-loop piston control with one GMT segment using MagAO-X’s PyWFS with and without simulated atmospheric turbulence. We show that the PyWFS was able to successfully control segment piston without turbulence within 12- to 33-nm RMS for 0 λ / D to 5 λ / D modulation, but was unsuccessful at controlling segment piston with generated ∼0.6 arcsec (median seeing conditions at the GMT site) and ∼1.2 arcsec seeing turbulence due to nonlinear modal cross-talk and poor pixel sampling of the segment gaps on the PyWFS detector. These results suggest that a PyWFS alone is not an ideal piston sensor for the GMT (and likely the TMT and ELT). Hence, a dedicated “second channel” piston sensor is required. We report the success of an alternate solution to control piston using a holographic dispersed fringe sensor (HDFS) while controlling all other modes with the PyWFS purely as a slope sensor (piston mode removed). This “second channel” WFS method worked well to control segment piston to within 50 nm RMS and ±10 μm dynamic range under simulated 0.6 arcsec atmospheric seeing (median seeing conditions at the GMT site). These results led to the inclusion of the HDFS as the official second channel piston sensor for the GMT NGWS WFS. This HDFS + PyWFS architecture should also work well to control piston petal modes on the ELT and TMT telescopes.

The time-resolved atomic, molecular and optical science instrument at the Linac Coherent Light Source.

The newly constructed time-resolved atomic, molecular and optical science instrument (TMO) is configured to take full advantage of both linear accelerators at SLAC National Accelerator Laboratory, the copper accelerator operating at a repetition rate of 120 Hz providing high per-pulse energy as well as the superconducting accelerator operating at a repetition rate of about 1 MHz providing high average intensity. Both accelerators power a soft X-ray free-electron laser with the new variable-gap undulator section. With this flexible light source, TMO supports many experimental techniques not previously available at LCLS and will have two X-ray beam focus spots in line. Thereby, TMO supports atomic, molecular and optical, strong-field and nonlinear science and will also host a designated new dynamic reaction microscope with a sub-micrometer X-ray focus spot. The flexible instrument design is optimized for studying ultrafast electronic and molecular phenomena and can take full advantage of the sub-femtosecond soft X-ray pulse generation program.

Theoretical Design of Graphene-Based Bi-Functional Tunable Terahertz Metasurfaces

Tunable multifunctional metasurface has wide application such as optical electromagnetics and material science. In this paper, a terahertz (THz) metasurface based on double graphene split-ring resonators (GSRRs) are theoretically demonstrated, integrating dual-band absorption and plasmon-induced transparency (PIT) filtering effect. The structure is composed of a monolayer of graphene arrays with periodic patterns and a metal ground surface partitioned by a silicon dioxide dielectric layer. When the initial structure of unit cell is three-layer sandwich structure (bottom metal plate), its dual-frequency absorption spectra appears two peaks at 2.50 THZ and 3.38 THz, which are 99.98% and 97.94%, respectively. Then the mechanism of double band absorption is explained by analyzing the distribution of surface current and electric intensity of the absorbent material. When the initial arrangement of the cell is a double layer structure (without the bottom metal plate), the PIT effect will occur when the incident wave is y-polarized. And in a certain range to achieve more than 90% of the transmission. In addition, CST simulations demonstrate that the designed model supports changing the operating frequency by adjusting the Fermi energy of graphene The dual-function terahertz metasurface proposed in this work has broad application prospects in broadband communication, terahertz imaging and industrial sensors.

Preface

Since 2020, we have had to adapt our activities due to the CoVid-19 pandemic. The prolonged restriction of movement has hampered our scientific research activities. We long for a venue where we can share and discuss optics and photonics, thus we are glad that the Indonesian Optical Society (InOS) biannual main meeting, the 13th International Symposium on Modern Optics and Its Applications (ISMOA) had been successfully held on 2-4 August 2021 virtually through video conference. With a theme of “Photonics for Better Lives”, this symposium was organized in collaboration with the Department of Electrical Engineering, Universitas Pelita Harapan, together with Institut Teknologi Bandung and Institut Teknologi Sepuluh Nopember as one of the International Day of Light (IDL) 2021 activities in Indonesia.The ISMOA meeting series is the flagship conference of the Indonesian Optical Society (InOS) which has been successfully organized twelve times. Since the first ISMOA held in 2001, for ten times, these meeting series have always been held at Institut Teknologi Bandung (ITB) in Bandung, Indonesia, wherein 2011 the Indonesian Optical Society was founded. Thereafter, to fulfil the mission of the society to disseminate the science of optics and its important contributions to the advances of science and technology in general, a rotating scheme of hosting the meeting by other universities and cities in Indonesia was started. This 13th meeting is the third time that the meeting was held outside of ITB. This 13th symposium was highlighted by 13 distinguished international scientists who delivered invited presentations on their latest research, namelyAslam BAIG (National Centre for Physics, Pakistan)Humeyra CAGLAYAN (Tampere Univ., Finland)Martijn DE STERKE (Univ. Sydney, Australia)Suganda JUTAMULIA (Omnivision Technologies, Inc., USA)Takashi KURODA (National Institute for Material Science, Japan)Laura M. LECHUGA (Catalan Institute of Nanoscience and Nanotechnology, Spain)David MARPAUNG (Univ. Twente, The Netherlands)Thomas PERTSCH (Friedrich-Schiller University Jena, Germany)Jonghwa SHIN (Korea Advanced Institute of Science and Technology, South Korea)Kaoru TAMADA (Kyushu University, Japan)Nelson TANSU (Univ. Adelaide, Australia)Thomas WHITE (Australian National University, Australia)Yuanlin ZHENG (Shanghai Jiao Tong University, P. R. China)out of which, 5 are Fellows of Optica.

Excited‐State‐Modulated Dual‐Wavelength Single‐Mode Lasing from a Single‐Component Organic Microbelt

AbstractSingle‐mode laser is of fundamental importance due to its beam quality and spectral purity. However, common lasers operate in multimode as the dimensions of most laser resonators are much larger than the operating wavelengths. Herein, the novel dual‐wavelength single‐mode lasing from a solution of self‐assembled single‐component microbelt that consists of excited‐state intramolecular proton transfer molecules is demonstrated. The large modulation of the gain regimes and the cooperative effect between gain and loss in the cavity are proven experimentally and theoretically to be effective strategies for achieving multiple‐wavelength and single‐mode operation. These results broaden optical science and provide new insight into the construction of multicolor lasers with high spectral purity for the on‐chip integrated photonic system.

Phonon-dressed states in an organic Mott insulator

In an electronic system of solids excited by a femtosecond laser pulse, new quantum states called photon-dressed states are created via the coupling of original electron wavefunctions and periodic electric fields of light. The study of photon-dressed states is a central issue in nonlinear optical science, as a coherent response associated with a photon-dressed state can cause ultrafast optical-switching phenomena. In general, however, phase-sensitive dynamics of photon-dressed states are difficult to observe due to their short lifetime. Here, we show that excitation of the organic Mott insulator potassium-tetracyanoquinodimethane with a strong mid-infrared pulse induces a couple of intramolecular vibrations, which add temporally periodic potentials to the electronic system, giving rise to phonon-dressed states in the picosecond time domain. Through sub-cycle spectroscopy using a phase-stable mid-infrared pulse as an excitation and an ultrashort visible pulse as a probe, we observe optical radiation consisting of four kinds of coherent oscillations with double, sum, and differential frequencies of two intramolecular vibrations. The probe-energy dependence of each oscillation can be well interpreted with phonon-dressed states in the framework of Floquet theory. These findings open a possibility for Floquet engineering in correlated electron materials with strong charge–phonon couplings.

Polarimetric Imaging Through Scattering Media: A Review

Imaging in scattering media has been a challenging and important subject in optical science. In scattering media, the image quality is often severely degraded by the scattering and absorption effects owing to the small particles and the resulting nonuniform distribution of the intensity or polarization properties. This study reviews the recent development in polarimetric imaging techniques that address these challenges. Specifically, based on the polarization properties of the backscattering light, polarimetric methods can estimate the intensity level of the backscattering and the transmittance of the media. They can also separate the target signal from the undesired ones to achieve high-quality imaging. In addition, the different designs of the polarimetric imaging systems offer additional metrics, for example, the degree/angle of polarization, to recover images with high fidelity. We first introduce the physical degradation models in scattering media. Secondly, we apply the models in different polarimetric imaging systems, such as polarization difference, Stokes vector, Mueller matrix, and deep learning-based systems. Lastly, we provide a model selection guideline and future research directions in polarimetric imaging.

Physics-informed recurrent neural network for time dynamics in optical resonances.

Resonance structures and features are ubiquitous in optical science. However, capturing their time dynamics in real-world scenarios suffers from long data acquisition time and low analysis accuracy due to slow convergence and limited time windows. Here we report a physics-informed recurrent neural network to forecast the time-domain response of optical resonances and infer corresponding resonance frequencies by acquiring a fraction of the sequence as input. The model is trained in a two-step multi-fidelity framework for high-accuracy forecast, using first a large amount of low-fidelity physical-model-generated synthetic data and then a small set of high-fidelity application-specific data. Through simulations and experiments, we demonstrate that the model is applicable to a wide range of resonances, including dielectric metasurfaces, graphene plasmonics and ultra-strongly coupled Landau polaritons, where our model captures small signal features and learns physical quantities. The demonstrated machine-learning algorithm can help to accelerate the exploration of physical phenomena and device design under resonance-enhanced light-matter interaction.

Optics in Africa, Part 2: Realizing the Promise

OPN talked with a number of African researchers about the prospects for advancing optical and photonic science on a diverse and changing continent.

Full‐Stokes Polarimetry for Visible Light Enabled by an All‐Dielectric Metasurface

Decoding arbitrary polarization information from an optical field has triggered unprecedented endeavors in polarization imaging, remote sensing, and information processing. Therefore, developing a polarization detection device with full on‐chip integration and miniaturization holds tremendous potential for many areas of optical sciences. Herein, a full‐Stokes polarimetry device for visible light based on an all‐dielectric metasurface is proposed. By combining both geometric phase and propagation phase modulation, the metasurface to provide two uncorrelated phase profiles for the two orthogonal states of input polarization is designed, which is then used to spatially separate the various polarization states of incident light. Through the use of a millimeter‐scale multiplexed metasurface array, successful characterization of the full polarization distribution of space‐variant polarization fields is further achieved. This proof‐of‐concept ultracompact and ultrathin metasurface is expected to open new pathways in full‐Stokes polarization detection, machine vision, and navigation.

Taking the Convergent Close-Coupling Method beyond Helium: The Utility of the Hartree-Fock Theory

The convergent close-coupling (CCC) method was initially developed to describe electron scattering on atomic hydrogen and the hydrogenic ions such as He+. The latter allows implementation of double photoionization (DPI) of the helium atom. For more complex single valence-electron atomic and ionic targets, the direct and exchange interaction with the inner electron core needs to be taken into account. For this purpose, the Hartree-Fock (HF) computer codes developed in the group of Miron Amusia have been adapted. In this brief review article, we demonstrate the utility of the HF technique by examples of electron scattering on Li and the DPI of the H− and Li− ions. We also discuss that modern-day computer infrastructure allows the associated CCC code, and others, to be readily run directly via the Atomic, Molecular and Optical Science Gateway.

Large-scale ab initio simulation of light–matter interaction at the atomic scale in Fugaku

In the field of optical science, it is becoming increasingly important to observe and manipulate matter at the atomic scale using ultrashort pulsed light. For the first time, we have performed the ab initio simulation solving the Maxwell equation for light electromagnetic fields, the time-dependent Kohn-Sham equation for electrons, and the Newton equation for ions in extended systems. In the simulation, the most time-consuming parts were stencil and nonlocal pseudopotential operations on the electron orbitals as well as fast Fourier transforms for the electron density. Code optimization was thoroughly performed on the Fujitsu A64FX processor to achieve the highest performance. A simulation of amorphous SiO2 thin film composed of more than 10,000 atoms was performed using 27,648 nodes of the Fugaku supercomputer. The simulation achieved excellent time-to-solution with the performance close to the maximum possible value in view of the memory bandwidth bound, as well as excellent weak scalability.

Four-Parameter Shifts Control Chaos and Lead to Physical Behaviour in a Dual-Ring Erbium-Doped Fiber Laser

We study on a four-parameter shift (FPS) chaos-control method to obtain control of a chaotic dual-ring erbium-doped fiber laser and lead to physics behaviours of two laser rings. To control two chaotic laser rings, the pump parameters and gain parameters of dual-ring lasers are modulated simultaneously by four shift digital signals. It is found that controls of the two chaotic laser rings are realized and physics behaviours of two laser rings can be guided by FPS. As a result, chaos is led to two periodic behaviours. And physics movements of dual-ring lasers are guided to period-4, period-5, period-6, period-7, and some high-order-period. The obtained results have a large helpfulness for people’ study of control of dynamics system, control of chaos, optic control science, laser physics, and erbium-doped fiber laser application.

Orbital angular momentum and beyond in free-space optical communications

AbstractOrbital angular momentum (OAM), which describes tailoring the spatial physical dimension of light waves into a helical phase structure, has given rise to many applications in optical manipulation, microscopy, imaging, metrology, sensing, quantum science, and optical communications. Light beams carrying OAM feature two distinct characteristics, i.e., inherent orthogonality and unbounded states in principle, which are suitable for capacity scaling of optical communications. In this paper, we give an overview of OAM and beyond in free-space optical communications. The fundamentals of OAM, concept of optical communications using OAM, OAM modulation (OAM modulation based on spatial light modulator, high-speed OAM modulation, spatial array modulation), OAM multiplexing (spectrally efficient, high capacity, long distance), OAM multicasting (adaptive multicasting,N-dimensional multicasting), OAM communications in turbulence (adaptive optics, digital signal processing, auto-alignment system), structured light communications beyond OAM (Bessel beams, Airy beams, vector beams), diverse and robust communications using OAM and beyond (multiple scenes, turbulence-resilient communications, intelligent communications) are comprehensively reviewed. The prospects and challenges of optical communications using OAM and beyond are also discussed at the end. In the future, there will be more opportunities in exploiting extensive advanced applications from OAM beams to more general structured light.

Early Modern Spectatorship: Interpreting English Culture 1500–1780. Ed. Ronald Huebert and David McNeil.

<i>Early Modern Spectatorship: Interpreting English Culture 1500–1780</i>. Ed. Ronald Huebert and David McNeil.

Zola and the Science of Painting

The article explores a paradox in Zola's writing: the resistance to advances in scientific theory by the author of Du Progrès dans les sciences et dans la poésie (1864), as the first of many such assimilations of scientific progress and artistic trends. This is exemplified by the challenge posed to his Naturalist aesthetic by Michel-Eugène Chevreul's seminal De la loi du contraste simultané des couleurs (1839), popularised during the period of Zola's most sustained art criticism. This radical revision of the science of optics is increasingly accommodated in contemporary painting, from 1880 onwards, at the very moment of Zola's disenchantment with Impressionism. Although L'Œuvre, his novel of 1886, is set in the Second Empire (consistent with the historical limits of Les Rougon-Macquart), Zola inserts into his narrative the theory of complementary colours, the awkward anachronism notwithstanding, to explain his fictional painter's creative impotence. In relation to the latter, the article looks in detail at the genesis and textual details of a key passage in the novel in which Zola's irony at the expense of Chevreul's theories is almost explicit. At least as telling is his response to unsolicited advice about them: ‘J’ai plus de confiance dans l'observation directe que dans la théorie’. One could hardly conjure up a more succinct summary of Zola's unreconstructed approach to the science of painting which simultaneously testifies to his own principles of representation.

Performance of microheaters for tunable on-chip interferometer

Mach-Zehnder interferometer (MZI) is a valuable practical tool in many optical science areas. In particular, high-contrast MZI are required for experimental realization of displacement-based quantum receivers that can discriminate weak coherent states of light with the minimum error rate. In this work we study phase modulators of tunable on-chip interferometer on silicon nitride (Si3N4) platform for telecom wavelength (1550 nm) consisting of several MZI. Phase modulators on one of the arms of MZI consists of microheaters and waveguide. Microheaters heat waveguides changing its refractive index due to thermo-optical effect providing a phase shift. We measure the bandwidth of phase modulators and study their operation in pulse mode.

ИССЛЕДОВАНИЕ ДЕЗИНФИЦИРУЮЩИХ СРЕДСТВ АВТОМАТИЗИРОВАННЫМ СПЕКТРОМЕТРОМ, РАБОТАЮЩИМ В ВИДИМОЙ ОБЛАСТИ СПЕКТРА

The paper highlights a modern spectral device for measuring the optical parameters of solid-state materials in liquid-phase. The development of these devices is promising for optical instrumentation and science in general, since these devices are informative, highly accurate and provide reliable information. In the paper the appearance, block diagram and lighting system of the spectrometer are presented. The spectral dependences of the transmission on the wavelength in the visible range of the spectrum for disinfectants Like, Grand, Aqualite (1% solutions) are obtained. For the analysis of the studied substances, specialized cuvettes with a working length from 0.1 to 0.5 mm and leucosapfir optical pads were used. The cuvettes were 0.05 mm thick. The spectrometer provided measurement of the transmission of disinfectants in the wavelength range of 380–760 nm with an error not worse than ΔТ ≤ 2%.