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.

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)
Editors' Picks
Laser printing based on curvature-driven shape transition of aluminum nanodiscs
Plasmonic color printing has several advantages over traditional color dyes printing: sub-wavelength resolution, the production of bright and non-fading colors. In general, the reflected color from metallic structures is determined by the plasmonic resonance, which is highly sensitive to the structure geometry and optical constants. Tuning the geometries and size of the plasmonic nanostructures is a means to tailoring absorption spectra in the visible frequency range.
Chinese Optics Letters
  • Jun. 03, 2021
  • Vol. 19, Issue 5 (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.21,2021
  • Chinese Optics Letters,Vol. 19, Issue 12
  • (2021)

Absorption induced by activated magnesium (Mg) in p-type layer contributes considerable optical internal loss in GaN-based laser didoes (LDs). An LD struc

Absorption induced by activated magnesium (Mg) in p-type layer contributes considerable optical internal loss in GaN-based laser didoes (LDs). An LD structure with distributed polarization doping (DPD) p-cladding layer (CL) without intentional Mg doping was designed and fabricated. The influence of anti-waveguide structure on optical confinement was studied by optical simulation. The threshold current density, slope efficiency of LDs with DPD p-CL and Mg-doped CL, respectively, were compared. It was found that LDs with DPD p-CL showed lower threshold current density but reduced slope efficiency, which was caused by decreasing internal loss and hole injection, respectively. show less

  • Jun.21,2021
  • Chinese Optics Letters,Vol. 19, Issue 12
  • (2021)

Dynamic plasmonics with the real-time active control capability of plasmonic resonances attract much interest in the community of physics, chemistry, and

Dynamic plasmonics with the real-time active control capability of plasmonic resonances attract much interest in the community of physics, chemistry, and material science. Among versatile reconfigurable strategies for dynamic plasmonics, the electrochemical driven strategies have garnered most of the attention. Here, we summarize three primary strategies to enable electrochemically dynamic plasmonics, including structural transformation, carrier-density modulation, and electrochemically active surrounding-media manipulation. The reconfigurable microstructures, optical properties as well as the underlying physical mechanisms are discussed in detail. We also summarize the most promising applications of dynamic plasmonics, including smart windows, structural color displays and chemical sensors. We suggest more research efforts towards the widespread applications of dynamic plasmonics as an outlook.show less

  • Jun.21,2021
  • Advanced Photonics

We demonstrate the non-mechanical beam steering and amplifier operation of a VCSEL-integrated slow-light amplifier with a resonant wavelength detuning des

We demonstrate the non-mechanical beam steering and amplifier operation of a VCSEL-integrated slow-light amplifier with a resonant wavelength detuning design, enabling the unidirectional coupling, continuous electrical beam steering and diffraction-limited good beam quality. The modelling result of the wavelength detuning design is presented for unidirectional coupling between a seed single-mode VCSEL and slow-light amplifier. We also present the detailed operating characteristics including the near-field and far field patterns, output power and lasing spectrum. The measured results exhibit the single-mode CW power of over 8mW, a continuous beam steering range of 16º, beam divergence below 0.1º and hence a record number of resolution points of over 200 as a solid-state VCSEL beam scanner. The integrated amplifier length is as small as 0.9 mm, thus we could expect much higher powers and higher resolution points by increasing the amplifier lengths.show less

  • Jun.21,2021
  • 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