On the Cover: Topological photonic states in artificial microstructures [Invited]
On the Cover: Extremely regular periodic surface structures in a large area efficiently induced on silicon by temporally shaped femtosecond laser
On the Cover: Resolving and weighing the quantum orbits in strong-field tunneling ionization
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

The image on the cover for Chinese Optics Letters Volume 19, Issue 5, indicates that Topological photonics provides a new opportunity for the examination of novel topological properties of matter, in which the energy band theory and ideas in topology are utilized to manipulate the propagation of photons.The image is based on original research by Hui Liu et al. presented in their paper "Topological photonic states in artificial microstructures [Invited]", Chinese Optics Letters 19 (5), 052602 (2021).

The image on the cover for Photonics Research Volume 9, Issue 5, indicates that Femtosecond laser-induced periodic surface structures (LIPSS) have several applications in surface structuring and functionalization. Three major challenges exist in the fabrication of regular and uniform LIPSS: enhancing the periodic energy deposition, reducing the residual heat, and avoiding the deposited debris. The image is based on original research by Yuchan Zhang et al. presented in their paper "Extremely regular periodic surface structures in a large area efficiently induced on silicon by temporally shaped femtosecond laser", Photonics Research 9 (5), 05000839 (2021).

The image on the cover for Advanced Photonics Volume 3, Issue 3, depicts tunneling ionization of an atom, as induced by a strong laser pulse. The complex hologram in the photoelectron momentum spectrum, which encodes rich structural and dynamic information of the atom, originates from the interference of the photoelectrons tunneling at different times during the laser pulse. By introducing a weak second harmonic field, the contributions of the photoelectrons tunneling at different times are identified, a significant step toward imaging the ultrafast dynamics in atoms and molecules with the photoelectron spectroscopy of tunneling ionization.The image is based on original research by Jia Tan et al. presented in their paper “Resolving and weighing the quantum orbits in strong-field tunneling ionization,” Adv. Photon.3(3), 035001 (2021).

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.

COL Highlights
SNR improvement of 8.2 dB in a self-mixing laser diode interferometer by using the difference signal at the output mirrors
The self-mixing interferometer (SMI) is a sort of optical radar capable of detecting extremely weak optical returns from a remotely located target and measuring the amplitude and phase of it. Different from the traditional radar based on launching a pulse to the target, the SMI uses a continuous coherent beam and operates as a coherent detector. Thanks to this feature, SMI has an unparalleled sensitivity to very small returns (down to 10-8 of the launched power) and can measure the phase – that is the optical pathlength down the target and back-with resolution of milliradian, that translates into optical pathlength attaining fractions of nanometers.
Chinese Optics Letters
  • Sep. 16, 2021
  • Vol. 19, Issue 9 (2021)
Spotlight on Optics
Bandpass-filter-integrated multiwavelength achromatic metalens
Chromatic aberration of an optical lens arises from the variation of focal length with respect to the wavelength of light caused by the material dispersion, which is a common phenomenon in white light imaging. This aberration will lead to the color blurring and severely degrade the image quality.
Photonics Research
  • Sep. 15, 2021
  • Vol. 9, Issue 7 (2021)
Editors' Picks
In-plane excitation of a topological nanophotonic corner state at telecom wavelengths in a cross-coupled cavity
Optical cavity, as one of the important elements of nanophotonics, is widely used in many fields, such as optical communications, sensing, quantum optics, and gravitational-wave detection. These applications have driven the development of high-performance cavity and cavity-based integrated devices, which is highly relevant to the control capability of cavity modes.
Photonics Research
  • Sep. 10, 2021
  • Vol. 9, Issue 8 (2021)
AP Highlights
Enhanced generation of nondegenerate photon pairs in nonlinear metasurfaces
Quantum nanophotonics is an active research field with emerging applications that range from quantum computing to imaging and telecommunications. This has motivated scientists and engineers to develop sources for entangled photons that can be integrated into nano-scale photonic circuits. Practical application of nanoscale devices requires a high photon-pair generation rate, room-temperature operation, and entangled photons emitted at telecommunications wavelengths in a directional manner.
Advanced Photonics
  • Sep. 08, 2021
  • Vol. 3, Issue 5 (2021)
AP Highlights
 Optical superoscillatory waves without side lobes along a symmetric cut
Optical superoscillation refers to a wave packet that can oscillate locally in a frequency exceeding its highest Fourier component. This intriguing phenomenon enables production of extremely localized waves that can break the optical diffraction barrier. Indeed, superoscillation has proven to be an effective technique for overcoming the diffraction barrier in optical superresolution imaging. The trouble is that strong side lobes accompany the main lobes of superoscillatory waves, which limits the field of view and hinders application.
Advanced Photonics
  • Sep. 06, 2021
  • Vol. 3, Issue 4 (2021)
Newest Articles
Blind zone-suppressed hybrid beam steering for solid-state Lidar

We demonstrate a blind zone-suppressed and flash-emitting solid-state Lidar based on lens-assisted beam-steering technology. As a proof-of-concept demonst

We demonstrate a blind zone-suppressed and flash-emitting solid-state Lidar based on lens-assisted beam-steering technology. As a proof-of-concept demonstration, with the design of a subwavelength-gap 1D long-emitter array and multiwavelength flash beam emitting, the device was measured to have 5% blind zone suppression, 0.06°/point-deflection step, and 4.2 μs scanning speed. In time-of-flight ranging experiments, Lidar systems have a field of view of 11.3°×8.1° (normal device) or 0.9°×8.1° (blind-zone suppressed device), far-field number of resolved points of 192, and a detection distance of 10 m. This work demonstrates the possibility that a new integrated beam-steering technology can be implemented in a Lidar without sacrificing other performance.show less

  • Sep.22,2021
  • Photonics Research,Vol. 9, Issue 9
  • 09001871 (2021)
Color centers in wide-bandgap semiconductors for subdiffraction imaging: a review

Solid-state atomic-sized color centers in wide-band-gap semiconductors, such as diamond, silicon carbide, and hexagonal boron nitride, are important platf

Solid-state atomic-sized color centers in wide-band-gap semiconductors, such as diamond, silicon carbide, and hexagonal boron nitride, are important platforms for quantum technologies, specifically for single-photon sources and quantum sensing. One of the emerging applications of these quantum emitters is subdiffraction imaging. This capability is provided by the specific photophysical properties of color centers, such as high dipole moments, photostability, and a variety of spectral ranges of the emitters with associated optical and microwave control of their quantum states. We review applications of color centers in traditional super-resolution microscopy and quantum imaging methods, and compare relative performance. The current state and perspectives of their applications in biomedical, chemistry, and material science imaging are outlined.show less

  • Sep.22,2021
  • Advanced Photonics,Vol. 3, Issue 5
  • 054001 (2021)
Effect of concentration on the formation time of diffraction rings in spatial self-phase modulation

A new unsaturated wind-chime model is proposed for calculating the formation time of the diffraction rings induced by spatial self-phase modulation (SSPM)

A new unsaturated wind-chime model is proposed for calculating the formation time of the diffraction rings induced by spatial self-phase modulation (SSPM) in molybdenum disulfide suspension. To optimize the traditional wind-chime model, the concentration variable of 2D materials was introduced. The results of the unsaturated wind-chime model match quite well with the SSPM experimental results of molybdenum disulfide. Based on this model, the shortest formation time of diffraction rings and their corresponding concentration and light intensity can be predicted using limited data. Theoretically, by increasing the viscosity coefficient of the solution, the response time of the diffraction ring, to reach the maximum value, can be significantly reduced. It has advanced significance in shortening the response time of photonic diodes.show less

  • Sep.22,2021
  • Chinese Optics Letters,Vol. 20, Issue 1
  • 011901 (2022)
Coherent dissipative soliton intermittency in ultrafast fiber lasers

As a universal phenomenon in nonlinear optical systems, intermittency is usually accompanied by the coherence loss such as soliton explosions in fiber las

As a universal phenomenon in nonlinear optical systems, intermittency is usually accompanied by the coherence loss such as soliton explosions in fiber lasers. Based on real-time spectroscopy, we revealed the coherent dissipative soliton intermittency in normal-dispersion fiber lasers. By increasing the pump strength, the intermittency transforms from the transient pulsation to the bi-stable soliton. It is demonstrated that the slow-gain effect dominates such coherent intermittency. Our results provide novel insights into laser physics, offering a promising approach for studying the bi-stable dissipative soliton.show less

  • Sep.22,2021
  • Chinese Optics Letters,Vol. 20, Issue 1
  • 011401 (2022)
Optics Physics Geography

We report on a power-scalable sub-100-fs laser in the 2-μm spectral range using a Tm3+-doped “mixed” (Lu,Sc)2O3 sesquioxide ceramic as an active medium. Pulses as short as 58 fs at 2076

We report on a power-scalable sub-100-fs laser in the 2-μm spectral range using a Tm3+-doped “mixed” (Lu,Sc)2O3 sesquioxide ceramic as an active medium. Pulses as short as 58 fs at 2076 nm with an average output power of 114 mW at a pulse repetition rate of ~ 82.9 MHz are generated by employing single-walled carbon nanotubes as a saturable absorber. Higher average power of 350 mW at 2075 nm is obtained at the expense of the pulse duration (65 fs). A maximum average power of 486 mW is achieved for a pulse duration of 98 fs and an optical conversion efficiency of 22.3%, representing the highest value ever reported from sub-100-fs mode-locked Tm-lasers.show less

  • Sep.22,2021
  • High Power Laser Science and Engineering

Abstract: We demonstrate integrated lithium niobate (LN) microring resonators with Q factors close to the intrinsic material absorption limit of LN. The microrings are fabricated on pri

Abstract: We demonstrate integrated lithium niobate (LN) microring resonators with Q factors close to the intrinsic material absorption limit of LN. The microrings are fabricated on pristine LN thin-film wafer thinned from LN bulk via chemo-mechanical etching without ion slicing and ion etching. A record-high Q factor up to 10<sup>8</sup> at the wavelength of 1550 nm is achieved because of the ultra-smooth interface of the microrings and the absence of ion-induced lattice damage, indicating an ultra-low waveguide propagation loss of ∼0.0034 dB/cm. The ultra-high Q microrings will pave the way for integrated quantum light source, frequency comb generation, and nonlinear optical processes.show less

  • Sep.22,2021
  • Chinese Optics Letters,Vol. 20, Issue 1
  • (2022)

In this paper, a novel liquid level sensor with ultra-high sensitivity is proposed. The proposed sensor is configured by slice-shaped composite long period fiber grating (SSC-LPFG). SSC

In this paper, a novel liquid level sensor with ultra-high sensitivity is proposed. The proposed sensor is configured by slice-shaped composite long period fiber grating (SSC-LPFG). SSC-LPFG is prepared by polishing on two opposite sides of composite multimode-single-mode-multimode (C-MSM) fiber structure using CO2 laser. The method improves the sensitivity of the sensor to external environment. Based on the simulation calculation, a liquid level sensor with a length of 3 mm is designed. The experimental transmission spectrum agrees well with the simulation result. The experimental results show that the sensitivity reaches 7080 pm/mm in the liquid level range of 0-1400 μm in water. The temperature sensitivity is 24.52 pm/°C in the range of 20-90 °C. Due to the ultra-high sensitivity, good linearity, and compact structure, the SSC-LPFG has the potential application in the field of high precision liquid level measurement.show less

  • Sep.22,2021
  • Chinese Optics Letters,Vol. 20, Issue 1
  • (2022)
The image on the cover for Chinese Optics Letters Volume 19, Issue 5, indicates that Topological photonics provides a new opportunity for the examination of novel topological properties of matter, in which the energy band theory and ideas in topology are utilized to manipulate the propagation of photons.The image is based on original research by Hui Liu et al. presented in their paper "Topological photonic states in artificial microstructures [Invited]", Chinese Optics Letters 19 (5), 052602 (2021).
  • Journal
  • 1th Sep,2021
The image on the cover for Photonics Research Volume 9, Issue 5, indicates that Femtosecond laser-induced periodic surface structures (LIPSS) have several applications in surface structuring and functionalization. Three major challenges exist in the fabrication of regular and uniform LIPSS: enhancing the periodic energy deposition, reducing the residual heat, and avoiding the deposited debris. The image is based on original research by Yuchan Zhang et al. presented in their paper "Extremely regular periodic surface structures in a large area efficiently induced on silicon by temporally shaped femtosecond laser", Photonics Research 9 (5), 05000839 (2021).
  • Journal
  • 1th Sep,2021