Power Coupling Efficiency Enhancement in Multimode Step-Index Fiber Using Refractive and Diffractive Microlenses

<table>Power coupling efficiency <svg height="9.875" id="M143" style="vertical-align:-2.29482pt" version="1.1" viewbox="0 0 7.9375 9.875" width="7.9375" xmlns="http://www.w3.org/2000/svg">
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</svg> is shown as a function of fibre relative core-cladding refractive-index difference <svg height="10.6625" id="M144" style="vertical-align:-0.0pt" version="1.1" viewbox="0 0 11.4125 10.6625" width="11.4125" xmlns="http://www.w3.org/2000/svg">
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</svg>  in percent for three different spot sizes fo the Gaussian beam at its waist, the wavelength of the beam, <svg height="11.0625" id="M145" style="vertical-align:-0.20064pt" version="1.1" viewbox="0 0 55.325001 11.0625" width="55.325001" xmlns="http://www.w3.org/2000/svg">
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<tspan style="font-size: 12.50px; " x="31.645094" y="0">8</tspan>
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</svg> <i>μ</i>m and <svg height="14.7875" id="M146" style="vertical-align:-3.13504pt" version="1.1" viewbox="0 0 60.724998 14.7875" width="60.724998" xmlns="http://www.w3.org/2000/svg">
<g transform="matrix(1.25,0,0,-1.25,0,14.7875)">
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<tspan style="font-size: 12.50px; " x="21.405136" y="0">4</tspan>
<tspan style="font-size: 12.50px; " x="27.656635" y="0">5</tspan>
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International Journal of Optics

fig7

Figure 7

Figure 7: Power Coupling Efficiency Enhancement in Multimode Step-Index Fiber Using Refractive and Diffractive Microlenses 