Photographic Demonstration of Intensity Distribution

1972 ◽  
Vol 12 ◽  
pp. 38-39
Keyword(s):  
Intensity Distribution

Structure images of Si, Ge and Mos2 crystals and some application to radiation damage studies

1978 ◽  
Vol 36 (1) ◽  
pp. 292-293 ◽  
Author(s):  
K. Izui ◽  
T. Nishida ◽  
S. Furuno ◽  
H. Otsu ◽  
S. Kuwabara
Keyword(s):  
Radiation Damage ◽  
Exposure Time ◽  
Gaussian Distribution ◽  
Intensity Distribution ◽  
Chromatic Aberration ◽  
Magnetic Lens

Recently we have observed the structure images of silicon in the (110), (111) and (100) projection respectively, and then examined the optimum defocus and thickness ranges for the formation of such images on the basis of calculations of image contrasts using the n-slice theory. The present paper reports the effects of a chromatic aberration and a slight misorientation on the images, and also presents some applications of structure images of Si, Ge and MoS2 to the radiation damage studies.(1) Effect of a chromatic aberration and slight misorientation: There is an inevitable fluctuation in the amount of defocus due to a chromatic aberration originating from the fluctuations both in the energies of electrons and in the magnetic lens current. The actual image is a results of superposition of those fluctuated images during the exposure time. Assuming the Gaussian distribution for defocus, Δf around the optimum defocus value Δf0, the intensity distribution, I(x,y) in the image formed by this fluctuation is given by

scholarly journals Design of a Secondary Freeform Lens of UV LED Mosquito-Trapping Lamp for Enhancing Trapping Efficiency

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 335 ◽  
Author(s):  
Wei-Hsiung Tseng ◽  
Diana Juan ◽  
Wei-Cheng Hsiao ◽  
Cheng-Han Chan ◽  
Hsin-Yi Ma ◽  
...  
Keyword(s):  
Light Intensity ◽  
Intensity Distribution ◽  
Light Emitting Diode ◽  
Trapping Efficiency ◽  
Axially Symmetric ◽  
Light Intensity Distribution ◽  
Light Emitting ◽  
Led Light ◽  
Uv Led ◽  
Freeform Lens

In this study, our proposed ultraviolet light-emitting diode (UV LED) mosquito-trapping lamp is designed to control diseases brought by insects such as mosquitoes. In order to enable the device to efficiently catch mosquitoes in a wider area, a secondary freeform lens (SFL) is designed for UV LED. The lens is mounted on a 3 W UV LED light bar as a mosquito-trapping lamp of the new UV LED light bar module to achieve axially symmetric light intensity distribution. The special SFL is used to enhance the trapping capabilities of the mosquito-trapping lamp. The results show that when the secondary freeform surface lens is applied to the experimental outdoor UV LED mosquito-trapping lamp, the trapping range can be expanded to 100π·m2 and the captured mosquitoes increased by about 300%.

scholarly journals A mode generator and multiplexer at visible wavelength based on all-fiber mode selective coupler

Nanophotonics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 973-981 ◽  
Author(s):  
Han Yao ◽  
Fan Shi ◽  
Zhaoyang Wu ◽  
Xinzhu Xu ◽  
Teng Wang ◽  
...  
Keyword(s):  
Phase Shift ◽  
Intensity Distribution ◽  
Linear Polarization ◽  
Mode Conversion ◽  
Polarization State ◽  
Stimulated Emission ◽  
Wavelength Multiplexing ◽  
Mode Converters ◽  
Fiber Mode ◽  
Vortex Beams

AbstractUsing an all-fiber mode selective coupler (MSC) at the visible band, here we experimentally demonstrate a generating and wavelength multiplexing scheme for the cylindrical vector (CV) and vortex beams (VBs). The proposed MSCs act as efficient mode converters to produce spectrally insensitive high-order modes (HOMs) at the wavelength ranging from 450 to 980 nm, which have broad operation bandwidth (more than 7 nm), high mode conversion efficiency (94%), and purity (98%), and low insert loss (below 0.5 dB). By adjusting the polarization state and the phase shift of linear polarization (LP)11 mode respectively, the donut-shaped CVs and circular-polarization VBs are achieved. The focused intensity distribution of the donut beam on the cross- and axial-sections is monitored by using a confocal system. The all-fiber solution of producing and multiplexing HOMs opens a new route for stimulated emission depletion microscopy applications.

scholarly journals Analysis of Predistortion Techniques on Fresnel Zone Plates in Ultrasound Applications

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5066
Author(s):  
José Miguel Fuster ◽  
Sergio Pérez-López ◽  
Francisco Belmar ◽  
Pilar Candelas
Keyword(s):  
Intensity Distribution ◽  
Fresnel Zone ◽  
Focal Depth ◽  
Acoustic Intensity ◽  
Fresnel Zone Plates ◽  
Therapeutic Applications ◽  
Zone Plates ◽  
Ultrasound Applications

In this work, we analyze the effect of predistortion techniques on the focusing profile of Fresnel Zone Plates (FZPs) in ultrasound applications. This novel predistortion method is based on either increasing or decreasing the width of some of the FZP Fresnel rings by a certain amount. We investigate how the magnitude of the predistortion, as well as the number and location of the predistorted rings, influences the lens focusing profile. This focusing profile can be affected in different ways depending on the area of the lens where the predistortion is applied. It is shown that when the inner area of the lens, closer to its center, is predistorted, this technique allows the control of the focal depth at the main focus. However, when the predistortion is applied to an area farther from the center of the lens, the acoustic intensity distribution among the main focus and the closest adjacent secondary foci can be tailored at a certain degree. This predistortion technique shows great potential and can be used to control, modify and shape the FZP focusing profile in both industrial and therapeutic applications.

scholarly journals Generation of Multiple Vector Optical Bottle Beams

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 218
Author(s):  
Svetlana N. Khonina ◽  
Alexey P. Porfirev ◽  
Sergey G. Volotovskiy ◽  
Andrey V. Ustinov ◽  
Sergey A. Fomchenkov ◽  
...  
Keyword(s):  
Intensity Distribution ◽  
Polarization State ◽  
Spatial Dynamics ◽  
Surface Structures ◽  
Optical Traps ◽  
Spatial Transformation ◽  
Optical Elements ◽  
Periodic Surface ◽  
Matter Interaction ◽  
Different Types

We propose binary diffractive optical elements, combining several axicons of different types (axis-symmetrical and spiral), for the generation of a 3D intensity distribution in the form of multiple vector optical ‘bottle’ beams, which can be tailored by a change in the polarization state of the illumination radiation. The spatial dynamics of the obtained intensity distribution with different polarization states (circular and cylindrical of various orders) were investigated in paraxial mode numerically and experimentally. The designed binary axicons were manufactured using the e-beam lithography technique. The proposed combinations of optical elements can be used for the generation of vector optical traps in the field of laser trapping and manipulation, as well as for performing the spatial transformation of the polarization state of laser radiation, which is crucial in the field of laser-matter interaction for the generation of special morphologies of laser-induced periodic surface structures.

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