The optical power distribution and scattering losses in symmetric channel waveguide X-junctions

1991 ◽  
Vol 23 (5) ◽  
pp. 649-656 ◽  
Author(s):  
S. Sh. Gevorgyan ◽  
A. B. Hovsepyan
Keyword(s):  
Power Distribution ◽  
Optical Power ◽  
Channel Waveguide ◽  
Symmetric Channel ◽  
Scattering Losses

Use of various keratometry data (ring and zone) in trifocal IOL calculation

2021 ◽  
pp. 53-56
Author(s):  
A.D. Loginova ◽  
◽  
S.V. Shukhaev ◽  
S.S. Kudlakhmedov ◽  
E.V. Boiko ◽  
...  
Keyword(s):  
Power Distribution ◽  
Optical Power ◽  
Iol Implantation ◽  
Universal Formula ◽  
Significant Difference ◽  
Trifocal Iol ◽  
Iol Calculation ◽  
Km Value ◽  
Tomographic Data ◽  
Corneal Refractive Power

Purpose. To compare the results of trifocal IOL calculation using various corneal tomographic data (ring and zone). Methods. This retrospective study involved 46 patients (46 eyes), underwent cataract surgery with trifocal IOL implantation (AcrySof IQ PanOptix). The calculation was performed using Tomey OA-2000 according to 2 formulas (Barrett II Universal, Olsen). Keratometry values included Km (the average of two main meridians of a cornea) provided by Pentacam HR Power Distribution Apex map, which describes total corneal refractive power (TCRP) with diameter of 3.0, 4.0 and 5.0 mm on a ring and zone. Mean (MAE) and median (MedAE) predicted postoperative refraction errors were assessed after surgery. Results. Mean Km value on 3 mm zone and ring was: 42.75±1,46 D and 42,91±1,43 D, respectively (p<0,0001). Mean Km on 4 mm zone and ring was: 42.6±1.5 D and 43.3 ± 1.5 D, respectively (p <0.005). Mean Km value on 5 mm zone and ring was: 43,09±1,5 D and 43,55±1,48 D, respectively (p<0,0001). Calculations using the Barrett II Universal formula revealed significant difference between MAE and MedAE of the predicted postoperative refraction on 5mm zone and ring (p=0.045). When using the Olsen formula in the calculations, significant difference was revealed using the Km data with a diameter of 3 mm and 5 mm (p=0.001 и p=0.009, respectively). The calculation on 3 mm ring was more accurate than for 3 mm zone. With a 5 mm diameter, the calculation is more accurate according to the zone data. Conclusion. Mean Km value on Power Distribution Apex map according to ring is significantly greater then according to zone. 1) The calculation of the trifocal IOL based on the TCRP zone data is reliably more accurate than the ring data according to both formulas (Barrett II Universal and Olsen) with a diameter of 5 mm. 2) According to the Olsen formula with a diameter of 3 mm, the calculation of the optical power of trifocal IOL based on TCRP ring data is more accurate. Key words: IOL calculation, Trifocal IOL, corneal topography

Influence of depth of intermediate layer on optical power distribution in W-type optical fibers

2012 ◽  
Vol 51 (20) ◽  
pp. 4896 ◽  
Author(s):  
Ana Simović ◽  
Alexandar Djordjevich ◽  
Svetislav Savović
Keyword(s):  
Optical Fibers ◽  
Power Distribution ◽  
Intermediate Layer ◽  
Optical Power

Coupling. Non-Symmetric Behaviour of a Joint Between Multimode Fibers

1984 ◽  
Vol 5 (3) ◽  
Author(s):  
G. Cancellieri ◽  
U. Ravaioli
Keyword(s):  
Power Distribution ◽  
Dispersion Compensation ◽  
Coupling Efficiency ◽  
Optical Power ◽  
Optical Source ◽  
Multimode Fibers ◽  
Intermodal Dispersion ◽  
Intentional Mode ◽  
Different Characteristics ◽  
Mode Mixing

SummaryWhen two different multimode fibers are jointed together, mode mixing and mode filtering take place, with different characteristics in the two directions, leading to a non-symmetric behaviour. A detailed analysis of the power transitions among the guided modes at the joint is presented here. Explicit formulas for coupling efficiency and intermodal dispersion compensation are derived. The intentional mode mixing which is produced by suitable beam-launchers, in order to reach an optical power distribution independent of that of the optical source, is also investigated.

scholarly journals Design of a Four-Branch Optical Power Splitter Based on Gallium-Nitride Using Rectangular Waveguide Coupling for Telecommunication Links

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Retno W. Purnamaningsih ◽  
Nji R. Poespawati ◽  
Elhadj Dogheche
Keyword(s):  
Gallium Nitride ◽  
Power Distribution ◽  
Optical Power ◽  
Power Input ◽  
Input Power ◽  
Propagation Length ◽  
Power Splitter ◽  
Excess Loss ◽  
Total Input ◽  
Rectangular Waveguides

This paper reports design of a simple four-branch optical power splitter using five parallel rectangular waveguides coupling in a gallium-nitride (GaN) semiconductor/sapphire for telecommunication links. The optimisation was conducted using the 3D FD-BPM method for long wavelength optical communication. The result shows that, at propagation length of 925 μm, the optical power input was successfully split into four uniform output beams, each with 24% of total input power. It is also shown that the relative output power distribution is almost stable through the C-band range. At the operating wavelength of 1.55 μm, the proposed power splitter has an excess loss lower than 0.2 dB. This study demonstrates the opportunity to develop optical interconnections from UV-Visible to near IR wavelengths.

The optical power distribution in a dark room

2012 ◽  
Author(s):  
Andrej Liner ◽  
Martin Papes ◽  
Jan Vitasek ◽  
Petr Koudelka ◽  
Jan Látal ◽  
...  
Keyword(s):  
Power Distribution ◽  
Optical Power ◽  
Dark Room

Two-dimensional optical power distribution of side-out-coupled radiation from tilted FBGs in multimode fibre

2003 ◽  
Vol 39 (8) ◽  
pp. 651 ◽  
Author(s):  
K. Zhou ◽  
G. Simpson ◽  
X. Chen ◽  
L. Zhang ◽  
I. Bennion
Keyword(s):  
Power Distribution ◽  
Optical Power ◽  
Two Dimensional

4 × 4 Plastic Optical Fiber Star Coupler Incorporated with a Common Polymer Waveguide Optical Power Distribution Region

2011 ◽  
Vol 30 (4) ◽  
pp. 265-277 ◽  
Author(s):  
Kwang Taek Kim ◽  
Boo Jeon Han ◽  
Min Kuk Kim ◽  
Young Ho Kim ◽  
Byeong Ha Lee ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Power Distribution ◽  
Optical Power ◽  
Plastic Optical Fiber ◽  
Polymer Waveguide
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