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.
We investigate the dynamics of a system consists of ultra-cold three-level atoms interacting with radiation fields. We derive the analytical expressions
We investigate the dynamics of a system consists of ultra-cold three-level atoms interacting with radiation fields. We derive the analytical expressions for the population dynamics of the system, particularly, in the presence and absence of nonlinear collisions by considering the rotating wave approximation (RWA). We also reanalyze the dynamics of the system beyond RWA and obtain the state vector of the system to study and compare the time behavior of population inversion. Our results show that the system undergoes two pure quantum phenomena i.e., the collapse-revival and macroscopic quantum self-trapping due to nonlinear collisional interactions. The occurrence of such phenomena strongly depends on the number of atoms in the system and also the ratio of interaction strengths in the considered system. Finally, we show that the result of the perturbed time evolution operator up to second-order is in agreement with the numerical solution of the Schr\"odinger equation. The results presented in the paper may be useful for the design of the devices that produce a coherent beam of bosonic atoms known as atom-laser.show less
Photoacoustic (PA) imaging (PAI) with handheld linear ultrasound (US) probe is widely used owing to its convenient and inherit dual modality capability. H
Photoacoustic (PA) imaging (PAI) with handheld linear ultrasound (US) probe is widely used owing to its convenient and inherit dual modality capability. However, the limited length of the linear probe makes PAI suffer from the limited view. In this study, we presented a simple method to substantially increase the view angle aided by two US reflectors. Both phantom and in vivo animal study results have demonstrated that the imaging quality can be greatly improved with the reflector without scarifying the imaging speed.show less
We introduce a nanoplasmonic isolator which consists of a cylindrical resonator placed close to a metal-dielectric-metal (MDM) waveguide. The material fil
We introduce a nanoplasmonic isolator which consists of a cylindrical resonator placed close to a metal-dielectric-metal (MDM) waveguide. The material filling the waveguide and resonator is a magneto-optical (MO) material, and the structure is under an externally applied static magnetic field. We theoretically investigate the properties of the structure, and show that the cavity mode without MO activity splits into two modes when MO activity is present. In addition, we find that the presence of the MDM waveguide leads to a second resonance due to the geometrical asymmetry caused by the existence of the waveguide. We also show that, when MO activity is present, the cavity becomes a traveling wave resonator. Thus, the transmission of the structure depends on the direction of the incident light, and the proposed structure operates as an optical isolator.show less
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