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).
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
The rapid development of high-intensity laser-generated particle and photon secondary sources has attracted widespread interest during the last 20 years n
The rapid development of high-intensity laser-generated particle and photon secondary sources has attracted widespread interest during the last 20 years not only due to fundamental science research but also because of the important applications of this developing technology. For instance, the generation of relativistic particle beams, betatron-type coherent X-ray radiation and high harmonic generation have attracted interest from various fields of science and technology owing to their diverse applications in biomedical, material science, energy, space, and security applications. In the field of biomedical applications in particular, laser-driven particle beams as well as laser-driven X-ray sources are a promising field of study. This article looks at the research being performed at the Institute of Plasma Physics and Lasers (IPPL) of the Hellenic Mediterranean University Research Centre. The recent installation of the ZEUS 45 TW laser system developed at IPPL offers unique opportunities for research in laser-driven particle and X-ray sources. This article provides information about the facility and describes initial experiments performed for establishing the baseline platforms for secondary plasma sources.show less
Transient response of an erbium-doped fiber amplifier (EDFA) is studied in an externally-modulated analog link. Double tones represented as transmitted ra
Transient response of an erbium-doped fiber amplifier (EDFA) is studied in an externally-modulated analog link. Double tones represented as transmitted radio frequency and dither signals are introduced. Extra modulation is generated owing to the EDFA’s transient response caused by a low-frequency dither signal. Therefore, the parasitic modulation is superposed to the output signals and may significantly affect in-band electrical spectra. Analytical and numerical solutions are both given, which agree well with experimental results. This work indicates that a suitable dither signal should be selected to maximize the carrier to intermodulation ratio. In-band spurious free dynamic range is optimized in the meantime.show less
In this paper, we present a suppression method for the thermal drift of an ultra-stable laser interferometer. The detailed analysis on the Michelson inter
In this paper, we present a suppression method for the thermal drift of an ultra-stable laser interferometer. The detailed analysis on the Michelson interferometer indicates that the change in optical path length induced by temperature variation can be effectively reduced by choosing proper thickness and/or incident angle of a compensator. Taking the optical bench of the Laser Interferometer Space Antenna Pathfinder as an example, we analyze the optical bench model with a compensator and show that the temperature coefficient of this laser interferometer can be reduced down to 1 pm/K with an incident angle of 0.267828 rad. The method presented in this paper can be used in the design of ultra-stable laser interferometers, especially for space-based gravitational waves detection.show less
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
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
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
In this paper, an effective method is proposed to generate specific periodical surface structures. 532nm linearly polarized laser is used to irradiate the silicon with pulse duration of
In this paper, an effective method is proposed to generate specific periodical surface structures. 532nm linearly polarized laser is used to irradiate the silicon with pulse duration of 10ns and repetition frequency of 10 Hz. LIPSS is observed when the fluence is 121 mJ/cm2 and pulses number of 1000 shots. The threshold of fluence for generating LIPSS gradually increases with the decrease of pulses number. In addition, the laser incident angle has a notable effect on the period of LIPSS which varies from 430 nm to 1578 nm as the incident angle ranges from 10° to 60° correspondingly. Besides, the reflectivity is reduced significantly on silicon with LIPSS. show less