2020 AP Editor-in-Chief Choice Award Released
On the Cover: A history of high-power laser research and development in the United Kingdom
On the Cover: Mode division multiplexing: from photonic integration to optical fiber transmission [Invited]
On the Cover: Experimental verification of group non-membership in optical circuits
On the Cover: Optical control of transverse motion of ionization injected electrons in a laser plasma accelerator

The 2020 Advanced Photonics Editor-in-Chief Choice Award has been released recently. In the end, an original research article and a review article were acknowledged to this honor. “Every article published in 2020 deserved this award,” Co-Editor-in-Chief Anatoly Zayats said. “Finally, we decided to recommend these two articles based on the level of attention and recognition they gained from the readers. There is no doubt that they reflect the development trends in the field of optics and photonics.”

The image on the cover of High Power Laser Science and Engineering Volume 9, Issue 2, indicates that many laboratories worldwide began the search for lasers using different materials, operating at different wavelengths. In the UK, academia, industry and the central laboratories took up the challenge from the earliest days to develop these systems for a broad range of applications. The image is based on original research by Colin N. Danson et al. presented in their paper "A history of high-power laser research and development in the United Kingdom", High Power Laser Science and Engineering 9 (2), 02000e18 (2021).

The image on the cover for Chinese Optics Letters Volume 19, Issue 9, indicates that different modes in a few-mode fiber (FMF) can be employed for mode division multiplexing (MDM) to overcome the capacity crunch of optical communications based on the traditional single-mode fiber (SMF). MDM can also be extended to photonic integration for obtaining improved density and efficiency, as well as interconnection capacity.The image is based on original research by Jiangbing Du et al. presented in their paper "Mode division multiplexing: from photonic integration to optical fiber transmission [Invited]", Chinese Optics Letters 19 (9), 091301 (2021).

The image on the cover for Photonics Research Volume 9, Issue 9, experimentally demonstrates the new verification process with a four-element group in an all-optical circuit. The new protocol is validated experimentally by observing a significant completeness-soundness gap between the probabilities of accepting elements in and outside the subgroup.The image is based on original research by Kai Sun et al. presented in their paper "Experimental verification of group non-membership in optical circuits", Photonics Research 9 (9), 09001745 (2021).

The image on the cover of High Power Laser Science and Engineering Volume 9, Issue 1, demonstrate an all-optical method for controlling the transverse motion of an ionization injected electron beam in a laser plasma accelerator by using the transversely asymmetrical plasma wakefield. The laser focus shape can control the distribution of a transversal wakefield. The image is based on original research by Jie Feng et al. presented in their paper "Optical control of transverse motion of ionization injected electrons in a laser plasma accelerator", High Power Laser Science and Engineering 9 (1), 010000e5 (2021).

On the Cover
Terahertz wavefront shaping with multi-channel polarization conversion based on all-dielectric metasurface
As an important parameter of electromagnetic waves, polarization not only describes the oscillation law of the electric field vector, but is also closely related to the spin angular momentum of the photons (circular polarization). It has extensive research and application value in the fields of optical imaging and quantum communication.
Photonics Research
  • Oct. 27, 2021
  • Vol. 19, Issue 10 (2021)
On the Cover
A history of high-power laser research and development in the United Kingdom
A large team of UK based scientists has gathered to document the history of high-powered lasers in the UK. The review was initiated as a celebration of the 60th anniversary of the first demonstration of the laser by Theodore Maiman in 1960. From the earliest days, UK academia, industry, national laboratories, and defense communities started to develop these systems for a broad range of applications (Colin N. Danson, Malcolm White, John R. M. Barr, et al. A history of high-power laser research and development in the United Kingdom[J]. High Power Laser Science and Engineering, 2021, 9(2): 02000e18).
Photonics Insights
  • Oct. 27, 2021
  • Vol. 9, Issue 2 (2021)
On the Cover
Overview of refractive index sensors comprising photonic crystal fibers based on the surface plasmon resonance effect
Over the past few decades, optical fibers have been widely applied to telecommunication, imaging, lasers, and sensing. Optical fibers constitute a platform to excite surface plasmon resonance (SPR) when plasmonic materials are coated on the surface of the fiber core, thus satisfying the need for miniaturization and integration. In particular, photonic crystal fiber (PCF) sensors based on SPR (PCF-SPR) have drawn much attention due to the flexibility of their structure. A PCF is essentially a microstructured optical fiber consisting of a silica core surrounded by a periodic lattice of air holes along the length of the fiber. PCFs are regarded as a desirable platform to excite surface plasmon resonance (SPR) because of easy realization of phase matching conditions between the fundamental core mode and the plasmonic mode, which is the most unique advantage over conventional optical fiber SPR sensors.
Chinese Optics Letters
  • Oct. 26, 2021
  • Vol. 19, Issue 10 (2021)
Editors' Picks
Measurement-device-independent quantum key distribution for nonstandalone networks
Loading and transmitting information using photons, quantum key distribution can share random key among users with unconditional security. The security is ensured by the quantum nature of photons and independent with computational complexity where any eavesdropping can be detected and quantified. Quantum key distribution has attracted extensive attention, fiber-based quantum key distribution networks using BB84 protocol has been deployed on a large scale, it takes the first step along the roadmap of Quantum Internet.
Photonics Research
  • Oct. 25, 2021
  • Vol. 9, Issue 10 (2021)
Editors' Picks
Identifying self-trapped excitons in 2D perovskites by Raman spectroscopy
Crystals with a 'soft' lattice are prone to distortion and deformation, which leads a strong excitons-phonons coupling. The strong coupling between the crystal lattice and excitons would lead to the formation of self-trapped excitons (STE), which are one type of bound state excitons. Unlike bound state excitons usually formed by binding to defects, STE can be produced even in a perfect crystal lattice. Since STE are produced by the coupling of excitons and phonons, they can be regarded as bound state excitons in an excited state. Once the excitons recombine, the lattice returns to its original state, and the self-trapped state disappears.
Chinese Optics Letters
  • Oct. 21, 2021
  • Vol. 19, Issue 10 (2021)
Newest Articles
Ultrawide-band silicon microring avalanche photodiode with linear photocurrent-wavelength response

We report a CMOS-compatible silicon microring-enhanced avalanche photodiode based on linear defect-state absorption in a p+pn+ junction, with high respons

We report a CMOS-compatible silicon microring-enhanced avalanche photodiode based on linear defect-state absorption in a p+pn+ junction, with high responsivities exceeding 1 A/W at telecommunication wavelengths. The large photogenerated currents give rise to giant thermo-optic nonlinearity in the microring resonator, resulting in a linear photocurrent-wavelength response spanning the full free spectral range of the microring. This unique photocurrent spectrum could enable novel applications in wavelength-resolved photodetection, such as compact on-chip spectrometers, linear chirp frequency laser source characterization, and low-cost refractometric sensors without requiring precise wavelength-tunable lasers.show less

  • Oct.28,2021
  • Photonics Research,Vol. 9, Issue 11
  • 11002325 (2021)
Adiabaticity in state preparation for spin squeezing of large atom ensembles

Spin-squeezed state is a many-body entangled state of great interest for precision measurements. Although the absolute sensitivity at the standard quantum

Spin-squeezed state is a many-body entangled state of great interest for precision measurements. Although the absolute sensitivity at the standard quantum limit is better for a larger atom number, the greater dominance of classical noises over atom projection noise makes it harder to achieve spin squeezing. Here, we show both theoretically and experimentally that adiabatic pulse control of the pump field in state preparation is indispensable to sufficient noise suppression, which is the prerequisite for spin squeezing. This technique is generally applicable to spin-squeezing experiments involving a large ensemble and is thus of significance for quantum metrology applications.show less

  • Oct.28,2021
  • Photonics Research,Vol. 9, Issue 11
  • 11002318 (2021)
Hybrid photonic-plasmonic cavities based on the nanoparticle-on-a-mirror configuration

Hybrid photonic-plasmonic cavities have emerged as a new platform to increase light–matter interaction capable to enhance the Purcell factor in a singular

Hybrid photonic-plasmonic cavities have emerged as a new platform to increase light–matter interaction capable to enhance the Purcell factor in a singular way not attainable with either photonic or plasmonic cavities separately. In the hybrid cavities proposed so far, the plasmonic element is usually a metallic bow-tie antenna, so the plasmonic gap—defined by lithography—is limited to minimum values of several nanometers. Nanoparticle-on-a-mirror (NPoM) cavities are far superior to achieve the smallest possible mode volumes, as plasmonic gaps smaller than 1 nm can be created. Here, we design a hybrid cavity that combines an NPoM plasmonic cavity and a dielectric-nanobeam photonic crystal cavity operating at transverse-magnetic polarization. The metallic nanoparticle can be placed very close (<1 nm) to the upper surface of the dielectric cavity, which acts as a low-reflectivity mirror. We demonstrate through numerical calculations of the local density of states that this hybrid plasmonic-photonic cavity exhibits quality factors Q above 103 and normalized mode volumes V down to 10-3, thus resulting in high Purcell factors (FP105), while being experimentally feasible with current technology. Our results suggest that hybrid cavities with sub-nanometer gaps should open new avenues for boosting light–matter interaction in nanophotonic systems.show less

  • Oct.28,2021
  • Photonics Research,Vol. 9, Issue 11
  • 11002296 (2021)
Use of KDP crystal as a Kerr nonlinear medium for compressing PW laser pulses down to 10 fs

The input pulse of the laser PEARL with energy of 18 J and pulse duration of about 60 fs was compressed to 10 fs after passage through a 4-mm-thick KDP cr

The input pulse of the laser PEARL with energy of 18 J and pulse duration of about 60 fs was compressed to 10 fs after passage through a 4-mm-thick KDP crystal and reflection at two chirped mirrors with sum dispersion of -200 fs2. The experiments were performed for the В-integral values from 5 to 19 without visible damage to the optical elements, which indicates that small-scale self-focusing is not a significant issue. It was shown that, by virtue of the low dispersion of the group velocity, the KDP crystal has some advantages over silica: a larger pulse compression coefficient, especially at a small value of the В-integral (B = 5, …, 9), lower absolute values of chirped mirror dispersion, and also a possibility to control the magnitude of nonlinearity and dispersion by changing crystal orientation.show less

  • Oct.28,2021
  • High Power Laser Science and Engineering,Vol. 9, Issue 4
  • 04000e54 (2021)
Optics Physics Geography

Large-amplitude electromagnetic radiofrequency fields are created by the charge-separation induced in interactions of high-intensity, short-pulse lasers with solid targets and have inte

Large-amplitude electromagnetic radiofrequency fields are created by the charge-separation induced in interactions of high-intensity, short-pulse lasers with solid targets and have intensity that decreases with the distance from target. Alternatively, it was experimentally proved very recently that charged particles emitted by petawatt laser-target interactions can be deposited on a capacitor-collector structure, far away from the target, and lead to the rapid (nanoseconds scale) generation of large quasi-static electric fields (MV/m), over wide regions. We demonstrate here the generation of both these two type of fields in experiments at the PHELIX Laser, with ∽100 J energy and ∽10<sup>19</sup> W/cm<sup>2</sup> intensity, for picoseconds laser pulses. Quasi-static fields, up to tens of kV/m, were here observed at distances larger than 1 m from target and resulted much higher than the radiofrequency component. This is of primary importance for inertial-confinement-fusion and laser-plasma-acceleration and also for promising applications to different scenarios.show less

  • Oct.28,2021
  • High Power Laser Science and Engineering

We proposed an aperiodic laser beam distribution, in which the laser beams are placed along Fermat spiral, to suppress the sidelobe power in the coherent beam combining. Owing to the ch

We proposed an aperiodic laser beam distribution, in which the laser beams are placed along Fermat spiral, to suppress the sidelobe power in the coherent beam combining. Owing to the changed distances between two consecutive beams, the condition of the sidelobe suppression are naturally satisfied. The Fermat spiral array were demonstrated to achieved a better sidelobe suppression than the periodic arrays, and the effects of various factors on the sidelobe suppression were analyzed numerically. Experiments were carried out to verify the sidelobe suppression by different Fermat spiral arrays and the results matched well with the simulations.show less

  • Oct.28,2021
  • Chinese Optics Letters,Vol. 20, Issue 2
  • (2022)

Large area and uniform monolayer MoS2 is of great importance for optoelectronic devices but is commonly suffering from rather weak photoluminescence. Here, by engineering the concentrat

Large area and uniform monolayer MoS2 is of great importance for optoelectronic devices but is commonly suffering from rather weak photoluminescence. Here, by engineering the concentration profiles of gaseous chemicals through extra trace amount of water, we demonstrate the uniform dendrite-type growth of monolayers MoS2 unraveled by the spatially resolved fluorescence spectroscopy, which exhibits macroscopic monolayer flakes (up to centimeter scale) with photoluminescence intensity of orders of magnitude higher than conventional CVD monolayers MoS2. Both spectroscopic evidence and theoretical models reveal that the fast-fractal dendrite growth can be ascribed to the extra introduced water sources that generate sufficient aqueous gas around the S-poor regions nearby the central-axis zone, leading to highly efficient Mo sources transport, accelerated S atom corrosion nearby grain edges and/or defect sites, as well as enhanced photoemission intensity. Our results may provide new insight for high throughput fabrication of MoS2 monolayers with high yield photoluminescence efficiency.show less

  • Oct.28,2021
  • Chinese Optics Letters,Vol. 20, Issue 1
  • (2022)

A hundred-watt level spatial mode switchable all-fiber laser is demonstrated based on a master oscillator power amplifier scheme. The performance of the amplifier with two seed lasers,

A hundred-watt level spatial mode switchable all-fiber laser is demonstrated based on a master oscillator power amplifier scheme. The performance of the amplifier with two seed lasers, i.e., with the acoustically induced fiber grating (AIFG) mode converter inside and outside of the seed laser cavity, is investigated. Real-time mode switching with millisecond scale switching time between LP<sub>01</sub> and LP<sub>11</sub> mode while operating in full power (> 100 W) is realized through an AIFG driven by radio frequency modulation. This work could provide a good reference for realizing high-power agile mode switchable fiber lasers for practical applications.show less

  • Oct.28,2021
  • Chinese Optics Letters,Vol. 20, Issue 2
  • (2022)
The 2020 Advanced Photonics Editor-in-Chief Choice Award has been released recently. In the end, an original research article and a review article were acknowledged to this honor. “Every article published in 2020 deserved this award,” Co-Editor-in-Chief Anatoly Zayats said. “Finally, we decided to recommend these two articles based on the level of attention and recognition they gained from the readers. There is no doubt that they reflect the development trends in the field of optics and photonics.”
  • Journal
  • 21th Oct,2021
The image on the cover of High Power Laser Science and Engineering Volume 9, Issue 2, indicates that many laboratories worldwide began the search for lasers using different materials, operating at different wavelengths. In the UK, academia, industry and the central laboratories took up the challenge from the earliest days to develop these systems for a broad range of applications. The image is based on original research by Colin N. Danson et al. presented in their paper "A history of high-power laser research and development in the United Kingdom", High Power Laser Science and Engineering 9 (2), 02000e18 (2021).
  • Journal
  • 19th Oct,2021