Reviews|22 Article(s)
Transformation optics from macroscopic to nanoscale regimes: a review
Jingjing Zhang, John B. Pendry, and Yu Luo
Transformation optics is a mathematical method that is based on the geometric interpretation of Maxwell’s equations. This technique enables a direct link between a desired electromagnetic (EM) phenomenon and the material response required for its occurrence, providing a powerful and intuitive design tool for the control of EM fields on all length scales. With the unprecedented design flexibility offered by transformation optics (TO), researchers have demonstrated a host of interesting devices, such as invisibility cloaks, field concentrators, and optical illusion devices. Recently, the applications of TO have been extended to the subwavelength scale to study surface plasmon-assisted phenomena, where a general strategy has been suggested to design and study analytically various plasmonic devices and investigate the associated phenomena, such as nonlocal effects, Casimir interactions, and compact dimensions. We review the basic concept of TO and its advances from macroscopic to the nanoscale regimes.
Advanced Photonics
  • Publication Date: Jan. 28, 2019
  • Vol.1 Issue, 1 014001 (2019)
Semiconductor nanolasers and the size-energy-efficiency challenge: a review
Cun-Zheng Ning
Semiconductor lasers, an important subfield of semiconductor photonics, have fundamentally changed many aspects of our lives and enabled many technologies since their creation in the 1960s. As in other semiconductor-based fields, such as microelectronics, miniaturization has been a constant theme, with nanolasers being an important frontier of research over the last decade. We review the progress, existing issues, and future prospects of nanolasers, especially in relation to their potential application in chip-scale optical interconnects. One of the important challenges in this application is minimizing the size and energy consumption of nanolasers. We begin with the application background of this challenge and then compare basic features of various semiconductor lasers. We present existing issues with nanolasers and discuss potential solutions to meet the size and energy-efficiency challenge. Our discussions cover a broad range of miniaturized lasers, including plasmonic nanolasers and lasers with two-dimensional monolayer gain materials, with focus on near-infrared wavelengths.
Advanced Photonics
  • Publication Date: Jan. 28, 2019
  • Vol.1 Issue, 1 014002 (2019)
Photonic tractor beams: a review
Weiqiang Ding, Tongtong Zhu, Lei-Ming Zhou, and Cheng-Wei Qiu
Usually, an unfocused light beam, such as a paraxial Gaussian beam, can exert a force on an object along the direction of light propagation, which is known as light pressure. Recently, however, it was found that an unfocused light beam can also exert an optical pulling force (OPF) on an object toward the source direction; the beam is accordingly named an optical tractor beam. In recent years, this intriguing force has attracted much attention and a huge amount of progress has been made both in theory and experiment. We briefly review recent progress achieved on this topic. We classify the mechanisms to achieve an OPF into four different kinds according to the dominant factors. The first one is tailoring the incident beam. The second one is engineering the object’s optical parameters. The third one is designing the structured material background, in which the light–matter interaction occurs, and the fourth one is utilizing the indirect photophoretic force, which is related to the thermal effect of light absorption. For all the methods, we analyze the basic principles and review the recent achievements. Finally, we also give a brief conclusion and an outlook on the future development of this field.
Advanced Photonics
  • Publication Date: Mar. 27, 2019
  • Vol.1 Issue, 2 024001 (2019)
Photonic implementation of boson sampling: a review
Daniel J. Brod, Ernesto F. Galvão, Andrea Crespi, Roberto Osellame, Nicolò Spagnolo, and Fabio Sciarrino
Boson sampling is a computational problem that has recently been proposed as a candidate to obtain an unequivocal quantum computational advantage. The problem consists in sampling from the output distribution of indistinguishable bosons in a linear interferometer. There is strong evidence that such an experiment is hard to classically simulate, but it is naturally solved by dedicated photonic quantum hardware, comprising single photons, linear evolution, and photodetection. This prospect has stimulated much effort resulting in the experimental implementation of progressively larger devices. We review recent advances in photonic boson sampling, describing both the technological improvements achieved and the future challenges. We also discuss recent proposals and implementations of variants of the original problem, theoretical issues occurring when imperfections are considered, and advances in the development of suitable techniques for validation of boson sampling experiments. We conclude by discussing the future application of photonic boson sampling devices beyond the original theoretical scope.
Advanced Photonics
  • Publication Date: May. 09, 2019
  • Vol.1 Issue, 3 034001 (2019)
Terahertz surface plasmonic waves: a review
Xueqian Zhang, Quan Xu, Lingbo Xia, Yanfeng Li, Jianqiang Gu, Zhen Tian, Chunmei Ouyang, Jiaguang Han, and Weili Zhang
Terahertz science and technology promise many cutting-edge applications. Terahertz surface plasmonic waves that propagate at metal–dielectric interfaces deliver a potentially effective way to realize integrated terahertz devices and systems. Previous concerns regarding terahertz surface plasmonic waves have been based on their highly delocalized feature. However, recent advances in plasmonics indicate that the confinement of terahertz surface plasmonic waves, as well as their propagating behaviors, can be engineered by designing the surface environments, shapes, structures, materials, etc., enabling a unique and fascinating regime of plasmonic waves. Together with the essential spectral property of terahertz radiation, as well as the increasingly developed materials, microfabrication, and time-domain spectroscopy technologies, devices and systems based on terahertz surface plasmonic waves may pave the way toward highly integrated platforms for multifunctional operation, implementation, and processing of terahertz waves in both fundamental science and practical applications. We present a review on terahertz surface plasmonic waves on various types of supports in a sequence of properties, excitation and detection, and applications. The current research trend and outlook of possible research directions for terahertz surface plasmonic waves are also outlined.
Advanced Photonics
  • Publication Date: Jan. 07, 2020
  • Vol.2 Issue, 1 014001 (2020)
Nonlinear optics in all-dielectric nanoantennas and metasurfaces: a review
Basudeb Sain, Cedrik Meier, and Thomas Zentgraf
Free from phase-matching constraints, plasmonic metasurfaces have contributed significantly to the control of optical nonlinearity and enhancement of nonlinear generation efficiency by engineering subwavelength meta-atoms. However, high dissipative losses and inevitable thermal heating limit their applicability in nonlinear nanophotonics. All-dielectric metasurfaces, supporting both electric and magnetic Mie-type resonances in their nanostructures, have appeared as a promising alternative to nonlinear plasmonics. High-index dielectric nanostructures, allowing additional magnetic resonances, can induce magnetic nonlinear effects, which, along with electric nonlinearities, increase the nonlinear conversion efficiency. In addition, low dissipative losses and high damage thresholds provide an extra degree of freedom for operating at high pump intensities, resulting in a considerable enhancement of the nonlinear processes. We discuss the current state of the art in the intensely developing area of all-dielectric nonlinear nanostructures and metasurfaces, including the role of Mie modes, Fano resonances, and anapole moments for harmonic generation, wave mixing, and ultrafast optical switching. Furthermore, we review the recent progress in the nonlinear phase and wavefront control using all-dielectric metasurfaces. We discuss techniques to realize all-dielectric metasurfaces for multifunctional applications and generation of second-order nonlinear processes from complementary metal–oxide–semiconductor-compatible materials.
Advanced Photonics
  • Publication Date: Apr. 03, 2019
  • Vol.1 Issue, 2 024002 (2019)
Roadmap for single-molecule surface-enhanced Raman spectroscopy
Yang Yu, Ting-Hui Xiao, Yunzhao Wu, Wanjun Li, Qing-Guang Zeng, Li Long, and Zhi-Yuan Li
In the near future, single-molecule surface-enhanced Raman spectroscopy (SERS) is expected to expand the family of popular analytical tools for single-molecule characterization. We provide a roadmap for achieving single molecule SERS through different enhancement strategies for diverse applications. We introduce some characteristic features related to single-molecule SERS, such as Raman enhancement factor, intensity fluctuation, and data analysis. We then review recent strategies for enhancing the Raman signal intensities of single molecules, including electromagnetic enhancement, chemical enhancement, and resonance enhancement strategies. To demonstrate the utility of single-molecule SERS in practical applications, we present several examples of its use in various fields, including catalysis, imaging, and nanoelectronics. Finally, we specify current challenges in the development of single-molecule SERS and propose corresponding solutions.
Advanced Photonics
  • Publication Date: Feb. 26, 2020
  • Vol.2 Issue, 1 014002 (2020)
Advances in soliton microcomb generation
Weiqiang Wang, Leiran Wang, and Wenfu Zhang
Optical frequency combs, a revolutionary light source characterized by discrete and equally spaced frequencies, are usually regarded as a cornerstone for advanced frequency metrology, precision spectroscopy, high-speed communication, distance ranging, molecule detection, and many others. Due to the rapid development of micro/nanofabrication technology, breakthroughs in the quality factor of microresonators enable ultrahigh energy buildup inside cavities, which gives birth to microcavity-based frequency combs. In particular, the full coherent spectrum of the soliton microcomb (SMC) provides a route to low-noise ultrashort pulses with a repetition rate over two orders of magnitude higher than that of traditional mode-locking approaches. This enables lower power consumption and cost for a wide range of applications. This review summarizes recent achievements in SMCs, including the basic theory and physical model, as well as experimental techniques for single-soliton generation and various extraordinary soliton states (soliton crystals, Stokes solitons, breathers, molecules, cavity solitons, and dark solitons), with a perspective on their potential applications and remaining challenges.
Advanced Photonics
  • Publication Date: Jun. 19, 2020
  • Vol.2 Issue, 3 034001 (2020)
Optical studies of semiconductor perovskite nanocrystals for classical optoelectronic applications and quantum information technologies: a review|On the Cover
Zengle Cao, Fengrui Hu, Chunfeng Zhang, Shining Zhu, Min Xiao, and Xiaoyong Wang
Semiconductor perovskite films are now being widely investigated as light harvesters in solar cells with ever-increasing power conversion efficiencies, which have motivated the fabrication of other optoelectronic devices, such as light-emitting diodes, lasers, and photodetectors. Their superior material and optical properties are shared by the counterpart colloidal nanocrystals (NCs), with the additional advantage of quantum confinement that can yield size-dependent optical emission ranging from the near-UV to near-infrared wavelengths. So far, intensive research efforts have been devoted to the optical characterization of perovskite NC ensembles, revealing not only fundamental exciton relaxation and recombination dynamics but also low-threshold amplified spontaneous emission and novel superfluorescence effects. Meanwhile, the application of single-particle spectroscopy techniques to perovskite NCs has helped to resolve a variety of optical properties for which there are few equivalents in traditional colloidal NCs, mainly including nonblinking photoluminescence, suppressed spectral diffusion, stable exciton fine structures, and coherent single-photon emission. While the main purpose of ensemble optical studies is to guide the smooth development of perovskite NCs in classical optoelectronic applications, the rich observations from single-particle optical studies mark the emergence of a potential platform that can be exploited for quantum information technologies.
Advanced Photonics
  • Publication Date: Sep. 21, 2020
  • Vol.2 Issue, 5 054001 (2020)
Spatiotemporal rotational dynamics of laser-driven molecules
Kang Lin, Ilia Tutunnikov, Junyang Ma, Junjie Qiang, Lianrong Zhou, Olivier Faucher, Yehiam Prior, Ilya Sh. Averbukh, and Jian Wu
Molecular alignment and orientation by laser fields has attracted significant attention in recent years, mostly due to new capabilities to manipulate the molecular spatial arrangement. Molecules can now be efficiently prepared for ionization, structural imaging, orbital tomography, and more, enabling, for example, shooting of dynamic molecular movies. Furthermore, molecular alignment and orientation processes give rise to fundamental quantum and classical phenomena like quantum revivals, Anderson localization, and rotational echoes, just to mention a few. We review recent progress on the visualization, coherent control, and applications of the rich dynamics of molecular rotational wave packets driven by laser pulses of various intensities, durations, and polarizations. In particular, we focus on the molecular unidirectional rotation and its visualization, the orientation of chiral molecules, and the three-dimensional orientation of asymmetric-top molecules. Rotational echoes are discussed as an example of nontrivial dynamics and detection of prepared molecular states.
Advanced Photonics
  • Publication Date: Apr. 11, 2020
  • Vol.2 Issue, 2 024002 (2020)