scholarly journals Band-stop angular filtering with hump volume Bragg gratings

2019 ◽  
Vol 7 ◽  
Author(s):  
Fan Gao ◽  
Xin Wang ◽  
Tiancheng Yu ◽  
Xiang Zhang ◽  
Xiao Yuan
Keyword(s):  
Near Field ◽  
Laser System ◽  
Bragg Gratings ◽  
Small Scale ◽  
Volume Bragg Gratings ◽  
Nonlinear Growth ◽  
Spatial Frequencies ◽  
Potential Applications ◽  
Laser Systems ◽  
Field Modulation

A band-stop angular filter (BSF) based on hump volume Bragg gratings (HVBGs) is proposed. Band-stop filtering in a two-stage amplifier laser system is discussed and simulated. Simulation results show that small-scale self-focusing effects in the laser system can be effectively suppressed with the BSF due to the control of fast nonlinear growth in a specific range of spatial frequencies in the laser beam. Near-field modulation of the output beam from the laser system was decreased from 2.69 to 1.37 by controlling the fast nonlinear growth of spatial frequencies ranging from $0.6~\text{mm}^{-1}$ to $1.2~\text{mm}^{-1}$ with the BSF. In addition, the BSF can be used in a plug-and-play scheme and has potential applications in high-power laser systems.

Near field angular filtering with volume Bragg gratings in photothermorefractive glass

2014 ◽  
Author(s):  
Xiang Zhang ◽  
Fan Gao ◽  
Jiansheng Feng ◽  
Kuaisheng Zou ◽  
Xiao Yuan
Keyword(s):  
Near Field ◽  
Bragg Gratings ◽  
Volume Bragg Gratings

High efficiency volume Bragg gratings for 2-micron laser systems

2016 ◽  
Author(s):  
Vadim Smirnov ◽  
Oleksiy Mokhun ◽  
Larissa Glebova ◽  
Ruslan Vasilyeu ◽  
Alexei Glebov ◽  
...  
Keyword(s):  
High Efficiency ◽  
Bragg Gratings ◽  
Volume Bragg Gratings ◽  
Laser Systems

Minimizing residual spectral drift in laser diode bars using femtosecond-written volume Bragg gratings in fused silica

2017 ◽  
Vol 42 (3) ◽  
pp. 623 ◽  
Author(s):  
Daniel Richter ◽  
Malte P. Siems ◽  
Wilko J. Middents ◽  
Maximilian Heck ◽  
Thorsten A. Goebel ◽  
...  
Keyword(s):  
Laser Diode ◽  
Bragg Gratings ◽  
Fused Silica ◽  
Volume Bragg Gratings

scholarly journals Double moiré localized plasmon structured illumination microscopy

Nanophotonics ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ruslan Röhrich ◽  
A. Femius Koenderink
Keyword(s):  
Near Field ◽  
Super Resolution ◽  
Reconstruction Algorithm ◽  
Structured Illumination ◽  
Structured Illumination Microscopy ◽  
Experimental Realization ◽  
Spatial Frequencies ◽  
Wide Range ◽  
Localized Plasmon ◽  
Plasmonic Grating

AbstractStructured illumination microscopy (SIM) is a well-established fluorescence imaging technique, which can increase spatial resolution by up to a factor of two. This article reports on a new way to extend the capabilities of structured illumination microscopy, by combining ideas from the fields of illumination engineering and nanophotonics. In this technique, plasmonic arrays of hexagonal symmetry are illuminated by two obliquely incident beams originating from a single laser. The resulting interference between the light grating and plasmonic grating creates a wide range of spatial frequencies above the microscope passband, while still preserving the spatial frequencies of regular SIM. To systematically investigate this technique and to contrast it with regular SIM and localized plasmon SIM, we implement a rigorous simulation procedure, which simulates the near-field illumination of the plasmonic grating and uses it in the subsequent forward imaging model. The inverse problem, of obtaining a super-resolution (SR) image from multiple low-resolution images, is solved using a numerical reconstruction algorithm while the obtained resolution is quantitatively assessed. The results point at the possibility of resolution enhancements beyond regular SIM, which rapidly vanishes with the height above the grating. In an initial experimental realization, the existence of the expected spatial frequencies is shown and the performance of compatible reconstruction approaches is compared. Finally, we discuss the obstacles of experimental implementations that would need to be overcome for artifact-free SR imaging.

scholarly journals Onset of the Mach Reflection of Zel’dovich–von Neumann–Döring Detonations

Entropy ◽  
2021 ◽  
Vol 23 (3) ◽  
pp. 314
Author(s):  
Tianyu Jing ◽  
Huilan Ren ◽  
Jian Li
Keyword(s):  
Hot Spot ◽  
Mach Reflection ◽  
Near Field ◽  
The Self ◽  
Small Scale ◽  
Mach Stem ◽  
Self Similarity ◽  
Von Neumann ◽  
Similarity Problem ◽  
Self Similar

The present study investigates the similarity problem associated with the onset of the Mach reflection of Zel’dovich–von Neumann–Döring (ZND) detonations in the near field. The results reveal that the self-similarity in the frozen-limit regime is strictly valid only within a small scale, i.e., of the order of the induction length. The Mach reflection becomes non-self-similar during the transition of the Mach stem from “frozen” to “reactive” by coupling with the reaction zone. The triple-point trajectory first rises from the self-similar result due to compressive waves generated by the “hot spot”, and then decays after establishment of the reactive Mach stem. It is also found, by removing the restriction, that the frozen limit can be extended to a much larger distance than expected. The obtained results elucidate the physical origin of the onset of Mach reflection with chemical reactions, which has previously been observed in both experiments and numerical simulations.

Widely tunable dual-wavelength operation of a high-power Tm:fiber laser using volume Bragg gratings

2010 ◽  
Vol 35 (14) ◽  
pp. 2388 ◽  
Author(s):  
Fei Wang ◽  
Deyuan Shen ◽  
Dianyuan Fan ◽  
Qisheng Lu
Keyword(s):  
High Power ◽  
Bragg Gratings ◽  
Dual Wavelength ◽  
Volume Bragg Gratings

scholarly journals Optical near-field mapping of plasmonic nanostructures prepared by nanosphere lithography

2018 ◽  
Vol 9 ◽  
pp. 1536-1543 ◽  
Author(s):  
Gitanjali Kolhatkar ◽  
Alexandre Merlen ◽  
Jiawei Zhang ◽  
Chahinez Dab ◽  
Gregory Q Wallace ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Hot Spots ◽  
Near Field ◽  
Nanosphere Lithography ◽  
Plasmonic Nanostructures ◽  
Far Field ◽  
Optical Images ◽  
Spatial Frequencies ◽  
Comparison Of The Results ◽  
Non Destructive

We introduce a simple, fast, efficient and non-destructive method to study the optical near-field properties of plasmonic nanotriangles prepared by nanosphere lithography. Using a rectangular Fourier filter on the blurred signal together with filtering of the lower spatial frequencies to remove the far-field contribution, the pure near-field contributions of the optical images were extracted. We performed measurements using two excitation wavelengths (532.1 nm and 632.8 nm) and two different polarizations. After the processing of the optical images, the distribution of hot spots can be correlated with the topography of the structures, as indicated by the presence of brighter spots at the apexes of the nanostructures. This technique is validated by comparison of the results to numerical simulations, where agreement is obtained, thereby confirming the near-field nature of the images. Our approach does not require any advanced equipment and we suggest that it could be applied to any type of sample, while keeping the measurement times reasonably short.

scholarly journals Polarization Controllable Device for Simultaneous Generation of Surface Plasmon Polariton Bessel-Like Beams and Bottle Beams

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 975 ◽  
Author(s):  
Peizhen Qiu ◽  
Taiguo Lv ◽  
Yupei Zhang ◽  
Binbin Yu ◽  
Jiqing Lian ◽  
...  
Keyword(s):  
Surface Plasmon ◽  
Surface Plasmon Polariton ◽  
Near Field ◽  
Polarized Light ◽  
Simultaneous Generation ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Spatially Distributed ◽  
Potential Applications ◽  
Plasmon Polariton

Realizing multiple beam shaping functionalities in a single plasmonic device is crucial for photonic integration. Both plasmonic Bessel-like beams and bottle beams have potential applications in nanophotonics, particularly in plasmonic based circuits, near field optical trapping, and micro manipulation. Thus, it is very interesting to find new approaches for simultaneous generation of surface plasmon polariton Bessel-like beams and bottle beams in a single photonic device. Two types of polarization-dependent devices, which consist of arrays of spatially distributed sub-wavelength rectangular slits, are designed. The array of slits are specially arranged to construct an X-shaped or an IXI-shaped array, namely X-shaped device and IXI-shaped devices, respectively. Under illumination of circularly polarized light, plasmonic zero-order and first-order Bessel-like beams can be simultaneously generated on both sides of X-shaped devices. Plasmonic Bessel-like beam and bottle beam can be simultaneously generated on both sides of IXI-shaped devices. By changing the handedness of circularly polarized light, for both X-shaped and IXI-shaped devices, the positions of the generated plasmonic beams on either side of device can be dynamically interchanged.

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