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4. Semiconductor LED chips are commonly coated with any optically transparent encapsulant. Assume that the refractive in
Posted: Tue Apr 26, 2022 7:15 pm
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- 4 Semiconductor Led Chips Are Commonly Coated With Any Optically Transparent Encapsulant Assume That The Refractive In 1 (57.98 KiB) Viewed 40 times
4. Semiconductor LED chips are commonly coated with any optically transparent encapsulant. Assume that the refractive index of the encapsulant is n=1.6 a. What is the reason for using an encapsulant b. Calculate the reflectance at the encapsulant-air boundary (Assume normal incidence) c. To reduce reflectance at the encapsulant-air boundary, one can use a second encapsulant forming a thin layer on top of the first encapsulant. The second encapsulant has a refractive index n2. Sketch the device having both encapsulants. d. Assume the reflectances of the two interfaces add up (R-Ri+R2). Give a formula for the total reflectance as a function of nz. e. Calculate the optimum value of n, that will minimize total reflection.