Misalignment Studies in Laser Diode to Upside Down Tapered Microlens Tipped Circular Core Photonic Crystal Fiber Excitation

Sumanta Mukhopadhyay

doi:10.37591/rrjophy.v7i3.1377

Abstract

By employing Gaussian field distributions for both the source and the fiber and also thealready derived ABCD matrix for upside down tapered microlens, we investigate theoreticallythe coupling optics involving a laser diode emitting practically interesting two differentwavelengths either 1.3 μm or 1.5 μm, and a series of circular core photonic crystal fibers withdifferent air filling ratio and lattice constant via upside down tapered microlens of twospecific taper lengths on the tip of such fiber in absence and presence of possible transverseand angular misalignments. It is observed that, for a fit taper length of 70.0 μm of upsidedown tapered microlens, photonic crystal fiber with air filling ratio of 0.35 and latticeconstant of 5.0 μm comes out to be the most suitable one to couple laser diode emitting lightof wavelength =1.3m. The coupling efficiency can reach to 94.63% with simultaneousoptimization of taper length and source position of specific lensed fiber. Such analysis whichas per our knowledge is the first theoretical investigation, will be extremely important inongoing investigations for the design of optimum launch optics involving upside down taperedmicrolens on the tip of photonic crystal fiber. Moreover, the results are extremely useful forassessing deeply the sensitivity of such coupler with reference to above kind of misalignments.Keywords: ABCD matrix, upside down tapered microlens, circular core photonic crystal fiber, transverse misalignment, angular misalignmentCite this ArticleSumanta Mukhopadhyay. Misalignment Studies in Laser Diode to Upside Down Tapered Microlens Tipped Circular Core Photonic Crystal Fiber Excitation. Research & Reviews: Journal of Physics. 2018; 7(3): 85–101p.