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.

HPL Highlights
Mandrel degradation model of combined fast and slow processes
Targets are physical base of laser inertial confinement fusion (ICF) research, whose quality has extremely important influences on the reliability and degree of precision for subsequent ICF experimental results. At present, the degradable mandrel technique with poly-α-methylstyrene (PAMS) degradation as the core has become one of the key technologies for fabricating ICF target. Its general process can be divided into three steps: first, hollow PAMS microspheres are prepared as mandrel, then plasma vapor deposition technology is used to prepare a coating (glow discharge polymer, GDP) with higher thermal stability on the surface, and finally PAMS are degraded leaving the hollow GDP target. Although many reports have been devoted to the related process, there are still two key problems in the actual preparation of GDP, that is, how to reduce the thermal degradation temperature of PAMS and how to avoid residues in PAMS degradation. Considering that the general nature of degradation corresponds to the breaking of chemical bonds, it is urgent to grasp the physical laws of the complex degradation process of PAMS at the atomic level and construct the reliable model of mandrel degradation.
High Power Laser Science and Engineering
  • May. 14, 2021
  • Vol. 9, Issue 1 (2021)
Editors' Picks
Optically addressed spatial light modulator based on nonlinear metasurfaces
Promoted by enthusiasm for future massive data processing by photons in parallel architectures, spatial light modulators (SLMs) were invented half a century ago. With the help of external control signals, such devices can manipulate light by modulating its amplitude, phase or polarization both spatially and temporally at will, which enables encoding information into an optical wavefront.
Photonics Research
  • May. 11, 2021
  • Vol. 9, Issue 4 (2021)
On the Cover
Optical beam splitting and asymmetric transmission in bi-layer metagratings
The asymmetric transmission of electromagnetic waves refers to the difference in transmittance or polarization state when they pass through media from two opposite directions. This asymmetric transmission effect has potential applications in the integrated photonic system of optical communication, information processing and all-optical computing, and has been one of the important research topics. The traditional devices with asymmetric response are too bulky to meet the needs of the integration and miniaturization of modern optical devices. In recent years, much effort has been devoted to metasurfaces used to the design of asymmetric transmission devices. Due to its flat and ultra-thin features, metasurfaces have unique application prospects in miniaturized and integrated devices compared with traditional optical components.
Chinese Optics Letters
  • May. 07, 2021
  • Vol. 19, Issue 4 (2021)
On the Cover
High-brightness red-emitting double-perovskite phosphor Sr2LaTaO6:Eu3+ with high color purity and thermal stability
At present, the environmental problems such as resource depletion, water pollution and air pollution caused by the development of nature resources have are raised great social concerns. Among the environmental issues, lighting electricity accounts for about 20% of global electricity consumption. Compared with traditional lighting sources such as incandescent lamps and fluorescent lamps, white light emitting diodes (LEDs) have many outstanding advantages like high energy efficiency, long working life, environmental friendliness, and etc. Therefore, the development of LEDs lighting is an effective solution to save power and protect the global environment.
Chinese Optics Letters
  • May. 07, 2021
  • Vol. 19, Issue 3 (2021)
Editors' Picks
High efficiency all-dielectric pixelated metasurface for near-infrared full-Stokes polarization detection
Polarization state, as one of the important properties of light, is widely used in many fields, such as satellite remote sensing, astronomy, polarization imaging, chemical analysis, and biomedical diagnosis. The traditional polarization measurement methods need to rotate the optical components several times to obtain multiple images of different polarization components of the target, so it is impossible to get real-time polarization information of the dynamic target.
Photonics Research
  • May. 06, 2021
  • Vol. 9, Issue 4 (2021)

A novel thin-film lithium niobate (TFLN) electro-optic modulator is proposed and demonstrated. LiNbO3-silica hybrid waveguide is adopted to maintain low o

A novel thin-film lithium niobate (TFLN) electro-optic modulator is proposed and demonstrated. LiNbO3-silica hybrid waveguide is adopted to maintain low optical loss for an electrode spacing as narrow as 3 µm, resulting in a low half-wave-voltage length product of only 1.7 V·cm. Capacitively loaded traveling-wave electrodes (CL-TWEs) are employed to reduce the microwave loss, while quartz substrate is used in place of silicon substrate to achieve velocity matching. The fabricated TFLN modulator with a 5-mm-long modulation region exhibits a half-wave-voltage of 3.4 V and merely less than 2 dB roll-off in electro-optic response up to 67 GHz. show less

  • May.15,2021
  • Chinese Optics Letters,Vol. 19, Issue 6
  • (2021)

At the mirrors of a Laser-Diode Self-Mixing Interferometer, the output beams carry anti-correlated (i.e., in phase opposition) interferometric signals, wh

At the mirrors of a Laser-Diode Self-Mixing Interferometer, the output beams carry anti-correlated (i.e., in phase opposition) interferometric signals, whereas the superposed noise fluctuations are (partially) correlated. Therefore, by using as an instrumental output of the interferometer the difference of the two, we double the amplitude of the self-mixing useful signal while the superposed noise is reduced. To validate the idea, we first calculate the noise reduction by means of a second-quantization model, finding that in a laser diode the SNR can be improved by 8.2-dB, typically. Then, we also carry out an experimental measurement of SNR and find very good agreement with the theoretical result. show less

  • May.15,2021
  • Chinese Optics Letters,Vol. 19, Issue 9
  • (2021)

Microrobots-assisted drug delivery and surgery have been always in the spotlight and are highly anticipated to solve the challenges of cancer in situ trea

Microrobots-assisted drug delivery and surgery have been always in the spotlight and are highly anticipated to solve the challenges of cancer in situ treatment. These versatile small biomedical robots are expected to realize direct access to the tumor or disease site for precise treatment, which requires real-time and high-resolution in vivo tracking as feedback for the microrobots’ actuation and control. Among current biomedical imaging methods, photoacoustic imaging (PAI) is presenting its outstanding performances in the tracking of micro-robots in the human body derived from its great advantages of excellent imaging resolution and contrast in deep tissue. In this review, we summarize the PAI techniques, imaging systems, and their biomedical applications in microrobots tracking in vitro and in vivo. From a robotic tracking perspective, we also provide some insight into the future of photoacoustic imaging technology in clinical applications.show less

  • May.15,2021
  • Chinese Optics Letters,Vol. 19, Issue 11
  • (2021)

In this article, taking advantage of the special magnetic shieldings and the optimal coil design of a transportable rubidium atomic fountain clock, the in

In this article, taking advantage of the special magnetic shieldings and the optimal coil design of a transportable rubidium atomic fountain clock, the intensity distribution in space and the fluctuations with time of the quantization magnetic field in Ramsey region were measured using the atomic magneton-sensitive transition method. In an approximately 310 mm length of the Ramsey region, a peak to peak magnetic field intensity of a 0.74 nT deviation in space and a 0.06 nT fluctuation with time were obtained. These results correspond to a second-order Zeeman frequency shift of approximately (2095±5.1)×10<sup>-17</sup>. This is an essential step in advancing the total frequency uncertainty of the fountain clock to the order of 10<sup>−17</sup>. show less

  • May.15,2021
  • 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 F&eacute;d&eacute;rale 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