Spatio-spectral Transformation of Non-collimated LightBeam Diffracted by Ultrasound in Birefringent Crystals

2021 ◽  
Author(s):  
Alexander Machikhin ◽  
Alexey Gorevoy ◽  
Grigoriy Martynov ◽  
Vitold Pozhar
Keyword(s):  
Spectral Transformation ◽  
Birefringent Crystals

scholarly journals Laser Pulse Shortening via Zero-Dispersion Phase Matching of Parametric Raman Interactions in Crystals

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 19
Author(s):  
Sergei N. Smetanin ◽  
Michal Jelínek ◽  
Dmitry P. Tereshchenko ◽  
Mikhail N. Ershkov ◽  
Václav Kubeček
Keyword(s):  
Laser Pulse ◽  
Short Pulse ◽  
Matching Condition ◽  
Phase Matching ◽  
Dispersion Phase ◽  
Birefringent Crystal ◽  
Raman Lasers ◽  
Birefringent Crystals ◽  
Phase Matching Condition ◽  
Ultra Short Pulse

We propose and study the conditions of zero-dispersion phase matching for parametric Raman interactions in birefringent crystals differing by anisotropy of zero-dispersion wavelength and allowing for the spectral tuning of the zero-dispersion phase-matching condition. We choose a highly birefringent crystal of calcite having a wide zero-dispersion anisotropy range for the demonstration of new effects of laser pulse shortening in parametric Raman lasers with spectrally tunable zero-dispersion phase matching. We demonstrate the anti-Stokes (1168 nm) and multi-Stokes (1629 nm) picosecond pulse shortening and self-separation of single 80-ps ultra-short pulse from the zero-dispersion phase-matched parametric Raman lasers that are based on the calcite crystal without using any electro-optical device.

Hydroxyfluorooxoborate Na[B3O3F2(OH)2][B(OH)3]: Optimizing the Optical Anisotropy with Heteroanionic Units for Deep Ultraviolet Birefringent Crystals

2021 ◽  
Author(s):  
Congcong Jin ◽  
Xuping Shi ◽  
Hao Zeng ◽  
Shujuan Han ◽  
Zhen Chen ◽  
...  
Keyword(s):  
Optical Anisotropy ◽  
Birefringent Crystals ◽  
Deep Ultraviolet

scholarly journals Hyperuricemia and Gout – Ins and Out

2020 ◽  
Vol 15 (2) ◽  
pp. 227-234
Author(s):  
Md Abdur Razzak ◽  
Quazi Audry Arafat Rahman ◽  
Fahtiha Nasreen
Keyword(s):  
Gouty Arthritis ◽  
Polarized Light ◽  
Acute Gout ◽  
Women Patients ◽  
Monosodium Urate ◽  
Tophaceous Gout ◽  
First Metatarsal ◽  
Birefringent Crystals ◽  
Inflammatory Drugs ◽  
Urate Crystals

Gout is a condition characterized by the deposition of monosodium urate crystals in the joints or soft tissue. The four phases of gout include asymptomatic hyperuricemia, acute gouty arthritis, intercritical gout and chronic tophaceous gout. The peak incidence occurs in patients 30 to 50 years old, and the condition is much more common in men than in women. Patients with asymptomatic hyperuricemia do not require treatment, but efforts should be made to lower their urate levels by encouraging them to make changes in diet or lifestyle. Acute gout most commonly affects the first metatarsal joint of the foot, but other joints are also commonly involved. Definitive diagnosis requires joint aspiration with demonstration of birefringent crystals in the synovial fluid under a polarized light microscope. Treatment includes nonsteroidal anti-inflammatory drugs (NSAIDs), colchicine, corticosteroids and analgesics. In patients without complications, NSAID therapy is preferred. JAFMC Bangladesh. Vol 15, No 2 (December) 2019: 227-234

scholarly journals AN ALGORITHM FOR GENERATING NATURAL COLOR IMAGES FROM FALSE COLOR USING SPECTRAL TRANSFORMATION TECHNIQUE WITH HIGHER POLYNOMIAL ORDER

2018 ◽  
Vol XLII-5 ◽  
pp. 643-648
Author(s):  
S. Kala ◽  
A. Kumar ◽  
A. K. Joshi ◽  
V. M. Bothale ◽  
B. G. Krishna
Keyword(s):  
Second Order ◽  
Color Images ◽  
Water Bodies ◽  
Blue Band ◽  
Spectral Transformation ◽  
False Color ◽  
Natural Color ◽  
Polynomial Transformation ◽  
Order Polynomial ◽  
Color Composite

<p><strong>Abstract.</strong> Satellite imageries in True color composite or Natural Color composite (NCC) serves the best combination for visual interpretation. Red, Green and Infrared channels form false color composite which might not be as useful as NCC to a non-remote sensing professional. As blue band is affected by large atmospheric scattering, satellites like IRS-LISS IV, SPOT do not have blue band. To generate NCC from such satellite data blue band must be simulated. Existing algorithms of spectral transformation do not provide robust coefficients leading to wrong NCC colors especially in water bodies. To achieve more robust coefficients, we have proposed new algorithm to generate NCC for IRS-LISS IV data using second order polynomial regression technique. Second order polynomial transformation functions consider even minor variability present in the image as compared to 1st order so that the derived coefficients are adjustable to accommodate spatial and temporal variability while generating NCC. In this study, Sentinel-2 image was used for deriving coefficients with blue band as dependent and green, red and infrared as independent variables. Simulated Sentinel band showed high accuracy with correlation of 0.93 and 0.97 for two test sites. Using the same coefficients, blue band was simulated for LISS-IV which also showed good correlation of 0.90 with sentinel original blue band. On comparing LISS-IV simulated NCC with simulated NCC from other algorithms, it was observed that higher order polynomial transformation was able to achieve higher accuracy especially for water bodies where expected color is green. Thus, proposed algorithms can be used for transforming false color image to natural color images.</p>

Waves and rays in uniaxial birefringent crystals

Optik ◽  
2007 ◽  
Vol 118 (10) ◽  
pp. 457-470 ◽  
Author(s):  
María C. Simon ◽  
Karin V. Gottschalk
Keyword(s):  
Birefringent Crystals

Pigmented fruiting bodies and birefringent crystals in a surgical wound: A clue to Aspergillus niger infection

2011 ◽  
Vol 38 (8) ◽  
pp. 604-606
Author(s):  
Michi M. Shinohara ◽  
Christopher J. Miller ◽  
John T. Seykora
Keyword(s):  
Aspergillus Niger ◽  
Fruiting Bodies ◽  
Surgical Wound ◽  
Birefringent Crystals

Propagation of ultrashort laser pulses in water: linear absorption and onset of nonlinear spectral transformation

2010 ◽  
Vol 49 (3) ◽  
pp. 513 ◽  
Author(s):  
Alexei V. Sokolov ◽  
Lucas M. Naveira ◽  
Milan P. Poudel ◽  
James Strohaber ◽  
Cynthia S. Trendafilova ◽  
...  
Keyword(s):  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Linear Absorption ◽  
Spectral Transformation ◽  
Ultrashort Laser

Comparison of outlier heartbeat identification and spectral transformation strategies for deriving heart rate variability indices for drivers at different stages of sleepiness

2018 ◽  
Vol 19 (sup1) ◽  
pp. S112-S119 ◽  
Author(s):  
Fabio Forcolin ◽  
Ruben Buendia ◽  
Stefan Candefjord ◽  
Johan Karlsson ◽  
Bengt Arne Sjöqvist ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Spectral Transformation
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