Chinese Laser Press announces a new review journal Photonics Insights
On the Cover: Thermo-optically tunable spectral broadening in a nonlinear ultra-silicon-rich nitride Bragg grating
On the Cover: Optical beam splitting and asymmetric transmission in bi-layer metagratings
On the Cover: Deep compressed imaging via optimized pattern scanning
On the Cover: High-brightness red-emitting double-perovskite phosphor Sr2LaTaO6:Eu3+ with high color purity and thermal stability [Invited]

Photonics Insights will be a high-quality,peer-reviewed, Diamond Open Access journal. It will feature review articles which present the current status of a given topic, with background, research progress, conclusions, and possible future developments.

The image on the cover of Photonics Research Volume 9, Issue 4, demonstrates temperature tunable spectral broadening using a nonlinear ultra-silicon-rich nitride device consisting of a 3-mm-long cladding-modulated Bragg grating and a 7-mm-long nonlinear channel waveguide. Provided by Y. Cao et al., researchers from Singapore University of Technology and Design, Ecole Polytechnique Fédérale de Lausanne, Institute of Microelectronics, A*STAR and The University of Sydney, the image is based on the research presented in their article "Thermo-optically tunable spectral broadening in a nonlinear ultra-silicon-rich nitride Bragg grating", Photonics Research 9(4) 04000596, doi 10.1364/PRJ.411073.

The image on the cover of Chinese Optics Letters Volume 19, Issue 4, indicates that a new type of optical bi-layer metasurface system is designed and studied, which is based on subwavelength metal slit arrays with phase-gradient modulation, referred to as metagratings (MGs). Provided by Q. Shi et al., researchers from Soochow University, Nanjing University of Aeronautics and Astronautics and North University of China, the image is based on the research presented in their article "Optical beam splitting and asymmetric transmission in bi-layer metagratings", Chinese Optics Letters 19(4) 042602, doi 10.3788/COL202119.042602.

The image on the cover of Photonics Research Volume 9, Issue 3, presents a new imaging modality, deep compressed imaging via optimized-pattern scanning, which can significantly increase the acquisition speed for a single-detector-based imaging system. Provided by K. Zhang, J. Hu and W. Yang, researchers from University of California, the image is based on the research presented in their article "Deep compressed imaging via optimized pattern scanning", Photonics Research 9(3) 03000B57, doi 10.1364/PRJ.410556.

The image on the cover of Chinese Optics Letters Volume 19, Issue 3, indicates that under near-ultraviolet excitation at 394 nm, optimal Sr2LaTaO6: 0.2Eu3+ phosphors emitted high-brightness red light around 613 nm with the International Commission on Illumination chromaticity coordinates (0.650, 0.349). Provided by Z. Zhang et al., researchers from Taiyuan University of Technology, the image is based on the research presented in their article "High-brightness red-emitting double-perovskite phosphor Sr2LaTaO6: 0.2Eu3+ with high color purity and thermal stability [Invited]", Chinese Optics Letters 19(3) 030003, doi 10.3788/COL202119.030003.

AP Highlights
Infrared upconversion imaging in nonlinear metasurfaces
The demand for detecting infrared (IR) light, invisible to human eyes, is constantly growing, due to a wide variety of applications ranging from food quality control and remote sensing to night vision devices and lidar. Commercial IR cameras require the conversion of infrared light to electrons and the projection of the resultant image on a display. This display blocks the transmission of visible light, thereby disrupting normal vision. Moreover, such IR detectors require low temperature and even cryogenic cooling due to the low energies of the IR photons, making IR detectors bulky and heavy.
Advanced Photonics
  • Jun. 22, 2021
  • Vol. 3, Issue 3 (2021)
Editors' Picks
Integrated thin-film lithium niobate Fabry–Perot modulator
With the rapid development of broadband centers, cloud-based services, the Internet of Things, and 5G services, network traffic is growing at a vigorous rate, which requires optical communication networks with higher capacity and lower power consumption. As the building block of optical communication networks, the function of the optical modulator is to realize the high-speed conversion of information from the electrical domain to the optical domain, and to convert data transmission from cable to ultra-low loss fiber. Lithium niobate (LiNbO3, LN) has been the dominant material platform for optical modulators widely used in optical fiber communications due to its excellent physical properties, such as its high electro-optic (EO) Pockels coefficient, low optical absorption, high intrinsic modulation bandwidth, and long-term material reliability. However, commercial LN modulators rely on titanium-diffused or proton-exchange waveguides. Such weakly confined optical waveguides are not beneficial to achieving strong electro-optic interaction. In the issue, such modulators have low modulation efficiency (~10V·cm) and large device sizes.
Chinese Optics Letters
  • Jun. 17, 2021
  • Vol. 19, Issue 6 (2021)
On the Cover
Wavefront-selective Fano resonant metasurfaces
Conventional Fano-resonant metasurfaces can only reflect light with a specific frequency, a planar wavefront, and linear polarization; the newly proposed metasurfaces can be tailored to be reflective to light with an arbitrary wavefront shape and circular polarization (doi: 10.1117/1.AP.3.2.026002)
Advanced Photonics
  • Jun. 16, 2021
  • Vol. 3, Issue 2 (2021)
HPL Highlights
Emission mechanism for the silicon He-α lines in a photoionization experiment
Photoionized plasma is an important existing form of plasmas in the universe. Celestial objects, such as AGN and X-ray binary, can emit strong radiation field and the high energy photos can ionize the surrounding gases. Thus, the low temperature gases can emit lines of highly ionized ions. The He-α lines are important method to diagnose the electron temperature and density of photoionized plasmas. As the development of the high energy density physics, the photoionized plasmas have been produced in the laboratories. In 2009, Fujioka et al. used the GEKKO-XII laser facility to produce photoionized silicon plasma. The experimental spectrum, the black solid line in Figure 1, is similar as that of Vela X-1, which is a typical X-ray binary. To simulate and illustrate the experimental spectrum is always a difficult problem, where the peak around 1855 eV (intercombination line) is always absent in the simulations.
High Power Laser Science and Engineering
  • Jun. 15, 2021
  • Vol. 9, Issue 1 (2021)
On the Cover
Topological Photonic States in Artificial Microstructures
Topology is an important branch of mathematics formed in the 19th century. It studies the invariant properties of geometric figures or space under continuous deformation. The idea of topological physics originated from the exciting discovery of the integer quantum Hall effect (IQHE) in condensed-state physics. Klitzing found that the two-dimensional (2D) electron gas in a strong perpendicular magnetic field has a quantized Hall conductance. The quantization originates from the non-trivial topology of the energy band structure, which is characterized by the Chern number according to the theoretical work of Thouless, Kohmoto, Nightingale, and den Nijs (TKNN). Haldane and Raghu creatively introduced the concept of topology to photonic crystals for the first time, as they proposed a photonics analogue of the quantum Hall effect in photonic crystals. Edge states appear at the domain wall between materials that have different Chern numbers and go through the topological bandgap in momentum space according to the bulk-edge correspondence.
Chinese Optics Letters
  • Jun. 04, 2021
  • Vol. 19, Issue 5 (2021)

We investigate the dynamics of a system consists of ultra-cold three-level atoms interacting with radiation fields. We derive the analytical expressions

We investigate the dynamics of a system consists of ultra-cold three-level atoms interacting with radiation fields. We derive the analytical expressions for the population dynamics of the system, particularly, in the presence and absence of nonlinear collisions by considering the rotating wave approximation (RWA). We also reanalyze the dynamics of the system beyond RWA and obtain the state vector of the system to study and compare the time behavior of population inversion. Our results show that the system undergoes two pure quantum phenomena i.e., the collapse-revival and macroscopic quantum self-trapping due to nonlinear collisional interactions. The occurrence of such phenomena strongly depends on the number of atoms in the system and also the ratio of interaction strengths in the considered system. Finally, we show that the result of the perturbed time evolution operator up to second-order is in agreement with the numerical solution of the Schr\"odinger equation. The results presented in the paper may be useful for the design of the devices that produce a coherent beam of bosonic atoms known as atom-laser.show less

  • Jun.22,2021
  • Chinese Optics Letters,Vol. 19, Issue 12
  • (2021)

Photoacoustic (PA) imaging (PAI) with handheld linear ultrasound (US) probe is widely used owing to its convenient and inherit dual modality capability. H

Photoacoustic (PA) imaging (PAI) with handheld linear ultrasound (US) probe is widely used owing to its convenient and inherit dual modality capability. However, the limited length of the linear probe makes PAI suffer from the limited view. In this study, we presented a simple method to substantially increase the view angle aided by two US reflectors. Both phantom and in vivo animal study results have demonstrated that the imaging quality can be greatly improved with the reflector without scarifying the imaging speed.show less

  • Jun.22,2021
  • Chinese Optics Letters,Vol. 19, Issue 12
  • (2021)

We introduce a nanoplasmonic isolator which consists of a cylindrical resonator placed close to a metal-dielectric-metal (MDM) waveguide. The material fil

We introduce a nanoplasmonic isolator which consists of a cylindrical resonator placed close to a metal-dielectric-metal (MDM) waveguide. The material filling the waveguide and resonator is a magneto-optical (MO) material, and the structure is under an externally applied static magnetic field. We theoretically investigate the properties of the structure, and show that the cavity mode without MO activity splits into two modes when MO activity is present. In addition, we find that the presence of the MDM waveguide leads to a second resonance due to the geometrical asymmetry caused by the existence of the waveguide. We also show that, when MO activity is present, the cavity becomes a traveling wave resonator. Thus, the transmission of the structure depends on the direction of the incident light, and the proposed structure operates as an optical isolator.show less

  • Jun.22,2021
  • Chinese Optics Letters,Vol. 19, Issue 8
  • (2021)

We report Q-switched mode-locked (QML) pulses generation in an Yb-doped multimode fiber (MMF) laser by using a graphene-deposited multimode microfiber (GM

We report Q-switched mode-locked (QML) pulses generation in an Yb-doped multimode fiber (MMF) laser by using a graphene-deposited multimode microfiber (GMM), for the first time to the best of our knowledge. The single-wavelength QML operation with the central wavelength tunable from 1028.81 nm to 1039.20 nm and the dual-wavelength QML operation with the wavelength spacing tunable from 0.93 nm to 5.79 nm are achieved due to the multimode interference filtering effect induced by the few-mode fiber and the MMF structure and the GMM in the cavity. Particularly, in the single-wavelength QML operation, the fifth harmonic is also realized owing to the high nonlinear effect of the GMM. The obtained results indicate that the QML pulses can be generated in the MMF laser and such a flexible tunable laser has promising applications in the optical sensing, measuring, and laser processing. show less

  • Jun.22,2021
  • Chinese Optics Letters,Vol. 19, Issue 12
  • (2021)
The image on the cover of Photonics Research Volume 9, Issue 4, demonstrates temperature tunable spectral broadening using a nonlinear ultra-silicon-rich nitride device consisting of a 3-mm-long cladding-modulated Bragg grating and a 7-mm-long nonlinear channel waveguide. Provided by Y. Cao et al., researchers from Singapore University of Technology and Design, Ecole Polytechnique Fédérale de Lausanne, Institute of Microelectronics, A*STAR and The University of Sydney, the image is based on the research presented in their article "Thermo-optically tunable spectral broadening in a nonlinear ultra-silicon-rich nitride Bragg grating", Photonics Research 9(4) 04000596, doi 10.1364/PRJ.411073.
  • Journal
  • 27th Apr,2021
The image on the cover of Chinese Optics Letters Volume 19, Issue 4, indicates that a new type of optical bi-layer metasurface system is designed and studied, which is based on subwavelength metal slit arrays with phase-gradient modulation, referred to as metagratings (MGs). Provided by Q. Shi et al., researchers from Soochow University, Nanjing University of Aeronautics and Astronautics and North University of China, the image is based on the research presented in their article "Optical beam splitting and asymmetric transmission in bi-layer metagratings", Chinese Optics Letters 19(4) 042602, doi 10.3788/COL202119.042602.
  • Journal
  • 27th Apr,2021