scholarly journals Influence of device to device interconnection elements on the system behavior and stability

2020 ◽  
Vol 18 (2) ◽  
pp. 843 ◽  
Author(s):  
Iraj Sadegh Amiri ◽  
Ahmed Nabih Zaki Rashed ◽  
Preecha Yupapin
Keyword(s):  
Focal Length ◽  
Beam Radius ◽  
Curvature Radius ◽  
Spherical Mirror ◽  
System Operation ◽  
Thin Lens ◽  
Crystal Stability ◽  
Lens Focal Length ◽  
Resonator System ◽  
Tilted Plane

<p>This work has presented the<strong> </strong>interaction between tangential/sagittal cylindrical thin lens in the titled plane parallel crystal. Stability criterion parameters are measured under the control of curvature radius of a spherical mirror, the thickness of the tilted plane crystal, the refractive index of tilted plane crystal, the thickness for a plate of matter and phase angle of the sagittal cylindrical thin lens. Beam radius waist is plotted against the focal length of the tangential cylindrical thin lens. Focal length for both thin lens in resonator crystal is optimized to upgrade the resonator system operation efficiency.</p>

scholarly journals Simulative Study of Simple Ring Resonator Based Brewster Plate for Power System operation Stability

2019 ◽  
Vol 16 (2) ◽  
pp. 1070 ◽  
Author(s):  
Iraj Sadegh Amiri ◽  
Ahmed Nabih Zaki Rashed
Keyword(s):  
Ring Resonator ◽  
Beam Radius ◽  
Curvature Radius ◽  
Spherical Mirror ◽  
Stability Parameters ◽  
Space Length ◽  
Simple Ring ◽  
Positive Effects ◽  
Operation Stability ◽  
Resonator System

<span>This study has outlined the simulative study of simple ring resonator based Brewster plate in the air. The obtained results are achieved with the variations of space length, curvature radius and phase angle of the </span><span>spherical mirror</span><span>. Beam radius criterion and stability parameters are measured with the variations of </span><span>refractive index</span><span> and thickness of Brewster plate in the air. The negative and positive effects of increasing operating parameters are observed on the performance of ring resonator system efficiency. </span>

scholarly journals Numerical investigation of V shaped three elements resonator for optical closed loop system

2019 ◽  
Vol 16 (3) ◽  
pp. 1392 ◽  
Author(s):  
Iraj Sadegh Amiri ◽  
Ahmed Nabih Zaki Rashed
Keyword(s):  
Numerical Investigation ◽  
Phase Angle ◽  
High Performance ◽  
Stability Parameter ◽  
Beam Radius ◽  
Curvature Radius ◽  
Negative Effects ◽  
System Parameters ◽  
Resonator System ◽  
The Stability

<span>This study have outlined numerical investigation of V shaped three element resonator. The stability parameter is measured against </span><span>back mirror curvature radius</span><span>, </span><span>back mirror phase angle</span><span>, </span><span>focusing length</span><span>, </span><span>focusing mirror phase angle</span><span>, </span><span>folding range</span><span> in both S plane and T plane. The stability parameter is changed in positive and negative trend under the operating system parameters. The stability parameter should be optimized in order to achieve high performance efficiency of resonator system. Beam radius variations are also measured versus </span><span>focusing range</span><span>, folding range, and back mirror phase angle. It is clear that the negative effects of increasing system parameters on beam radius variation in both S plane and T plane. </span>

scholarly journals Z shaped like resonator with crystal in the presence of flat mirror based standing wave ratio for optical antenna systems

2020 ◽  
Vol 17 (3) ◽  
pp. 1405 ◽  
Author(s):  
Iraj Sadegh Amiri ◽  
Ahmed Nabih Zaki Rashed ◽  
Preecha Yupapin
Keyword(s):  
Standing Wave ◽  
Cavity Length ◽  
Beat Frequency ◽  
Stability Parameter ◽  
Beam Radius ◽  
Curvature Radius ◽  
Spherical Mirror ◽  
Optical Antenna ◽  
Flat Mirror ◽  
Intermode Beat

<span>This study has outlined the Z resonator shaped with Brewster crystal in the presence of flat mirror for measuring the standing wave ratio. Stability parameter and beam radius are simulated versus thickness, refractive index of the crystal and first and second folding ranges. Beam radius variations are studied against phase angle and curvature radius of spherical mirror in T and S planes. Intermode beat frequency of the system is 216.276 MHz and total cavity length is 693.078 mm. It is important the standing wave ratio is dependent on stability parameter and beam radius variations. </span>

scholarly journals Evaluating effects of focal length and viewing angle in a comparison of recent face landmark and alignment methods

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Xiang Li ◽  
Jianzheng Liu ◽  
Jessica Baron ◽  
Khoa Luu ◽  
Eric Patterson
Keyword(s):  
Focal Length ◽  
Ground Truth ◽  
Detection Methods ◽  
Viewing Angle ◽  
Deep Convolutional Neural Networks ◽  
Landmark Detection ◽  
High Performing ◽  
Detection Techniques ◽  
And Performance ◽  
Lens Focal Length

AbstractRecent attention to facial alignment and landmark detection methods, particularly with application of deep convolutional neural networks, have yielded notable improvements. Neither these neural-network nor more traditional methods, though, have been tested directly regarding performance differences due to camera-lens focal length nor camera viewing angle of subjects systematically across the viewing hemisphere. This work uses photo-realistic, synthesized facial images with varying parameters and corresponding ground-truth landmarks to enable comparison of alignment and landmark detection techniques relative to general performance, performance across focal length, and performance across viewing angle. Recently published high-performing methods along with traditional techniques are compared in regards to these aspects.

Absorption efficiency analysis and optical resonator simulation of Ho:YLF laser pumped with Tm:fiber laser

Laser Physics ◽  
2021 ◽  
Vol 32 (1) ◽  
pp. 015001
Author(s):  
Majid Babaiy Tooski ◽  
Abbas Maleki ◽  
Abdolah Eslami Majd ◽  
Hassan Ebadian
Keyword(s):  
Slope Efficiency ◽  
Doping Concentration ◽  
Continuous Wave ◽  
Focal Length ◽  
Beam Width ◽  
Absorption Efficiency ◽  
Optical Resonator ◽  
Threshold Power ◽  
Continuous Wave Operation ◽  
Lens Focal Length

Abstract In this paper, a Tm:fiber laser pumped Ho:YLF laser is simulated. The absorption efficiency, optimum crystal length, and optical resonator are analytically studied and simulated using LASCAD software, and the atomic-level degeneracies are considered in evaluating the absorption efficiency. In this way, the absorption efficiencies of 65% and 87% are obtained for single-pass 30 mm Ho:YLF crystal with doping concentration 0.5% and 1% respectively. These calculated efficiencies are verified by our experimental measurements and they coincide with acceptable errors. To estimate a proper length for the Ho:YLF crystal with specified doping concentration, the up-conversion, and the reabsorption effects are considered. As a result, we find the 30 mm length crystal is suited for reducing the absorption threshold and prohibiting reabsorption while saturation is controlled. The threshold power and slope efficiency for 65 W pumped powers are calculated by LASCAD software, and the thermal lens focal length of −665 mm is obtained. For a nearly constant beam width inside the cavity and suitable beam overlap efficiency, a concave-concave configuration is chosen for the optical resonator. In the continuous-wave operation, the output power is funded to be 38.4 W and the slope efficiency would be 66%.

Measurement of Lens Focal Length with Hartmann-Shack Wave Front Sensor Based on 4F System

Applied laser ◽  
2013 ◽  
Vol 33 (2) ◽  
pp. 212-215
Author(s):  
许江华 Xu Jianghua ◽  
朱岚 Zhu Lan ◽  
陈家璧 Chen Jiabi ◽  
庄松林 Zhuang Songlin
Keyword(s):  
Wave Front ◽  
Focal Length ◽  
Lens Focal Length

Comparative Study of Some Fiber-Optic Remote Raman Probe Designs. Part II: Tests of Single-Fiber, Lensed, and Flat- and Bevel-Tip Multi-Fiber Probes

1996 ◽  
Vol 50 (7) ◽  
pp. 849-860 ◽  
Author(s):  
Thomas F. Cooney ◽  
H. Trey Skinner ◽  
S. M. Angel
Keyword(s):  
Fiber Optic ◽  
Focal Point ◽  
Focal Length ◽  
Numerical Aperture ◽  
Optical Filters ◽  
Organic Liquids ◽  
Raman Signal ◽  
Immersion Medium ◽  
Lens Focal Length ◽  
Overlap Model

We compare relative performances of flat-tipped, beveled (two-fiber and six-around-one), and single-lensed focused fiber-optic Raman probes and, where feasible, evaluate the utility of optical filters for reducing fiber background. The sensitivity profile of each probe is determined by measuring the relative intensity of light backscattered off a flat surface as a function of distance from the probe tip. The experimental results are compared with a simple light-cone-overlap model incorporating fiber numerical aperture, fiber and immersion medium refractive indices, separation between excitation and collection fibers, number of fibers, and fiber bevel angle and/or lens focal length. The model and sensitivity profiles are used to interpret the sampling regions for Raman spectra obtained by using each of the probes with a clear, transparent sample (single-crystal sparry calcite), a white, partially transparent sample (acetaminophen tablet), and a set of organic liquids of varying refractive index. The sensitivity of the tested commercial lensed probe drops off symmetrically about the focal point. For both solid samples, the intensity of fiber background follows a profile determined primarily by laser backscattering off the surface, whereas the sample Raman signal follows a profile dependent upon sampling depth.

Numerical Simulations of Fractional Fourier Transform of Hypergeometric-Gaussian Beam

2013 ◽  
Vol 765-767 ◽  
pp. 780-784 ◽  
Author(s):  
Zhen Feng Yang ◽  
Wen Dan Miao ◽  
Zhen Jun Yang ◽  
Shu Min Zhang
Keyword(s):  
Fourier Transform ◽  
Numerical Simulations ◽  
Gaussian Beam ◽  
Intensity Distribution ◽  
Fractional Fourier Transform ◽  
Focal Length ◽  
Beam Width ◽  
Laser Beams ◽  
New Type ◽  
Lens Focal Length

The fractional Fourier transform (FRFT) of a new type of laser beams called the hypergeometric-Gaussian beam (HyGGB) is investigated in detail. The analytical expression for the FRFT of a HyGGB is derived. The properties of a HyGGB in the FRFT plane with different parameters are illustrated. The results show that the intensity distribution of a HyGGB in the FRFT plane strongly depends on the fractional order, the lens focal length and the initial beam width.

The visual system and paleoecology of the Silurian ostracod Primitiopsis planifrons

2009 ◽  
Vol 83 (3) ◽  
pp. 414-421 ◽  
Author(s):  
Gengo Tanaka ◽  
David J. Siveter ◽  
Andrew R. Parker
Keyword(s):  
Visual System ◽  
Water Depth ◽  
Spherical Aberration ◽  
Focal Length ◽  
Relative Size ◽  
Spherical Mirror ◽  
Subtidal Zone ◽  
Ontogenetic Change ◽  
Geological Evidence ◽  
Independent Test

Here we report the first detailed reconstruction of the eye and visual system of a Paleozoic ostracod, namely the dimorphic primitiopsid (Palaeocopa) Primitiopsis planifrons Jones, 1887. Evidence from the cuticular lens morphology and its position on the valve suggests that P. planifrons had a naupliar eye, which is the most common optical system in crustaceans. the characters of the eye, such as the separated cuticular lens on each valve and the strongly calcified nature of the lens and its diameter, are concordant with that of some Recent podocopid ostracods in which a divided type of naupliar eye is present. Ray tracing of the reconstructed cuticular lens of the primitiopsid species demonstrates strong spherical aberration and a very long focal length (as in the eye of podocopids), which implies the presence of a spherical mirror (tapetum) below the lens. Study of the ontogenetic change of the valve thickness aids the suggestion that P. planifrons was nektobenthic. the size of its cuticular lens in relation to that of living podocopid ostracods, and the water depth at which these Recent forms occur, indicates that P. planifrons may have lived in a relatively shallow, well lit environment such as the deep subtidal zone. These interpretations are consistent with supposed paleoenvironmental conditions derived from geological evidence. Thus, analysis of the nature and relative size of the eye gives an independent test to help identify paleoenvironmental parameters of long extinct ostracods.

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