We present simple and complete empirical relations to predict the angle of beam divergence in terms of normalized frequency and aspect ratio of a single-mode trapezoidal index fiber. This is done for the far-field characterization over a long range of normalized frequencies without the calculation of normalized spot sizes. On comparison, we observe an excellent match of our results with exact values establishing the validity of our formulation. The formulation should attract attention as a simple alternative to the rigorous methods of estimating the angle of beam divergence for such fibers. It can be widely used by system users and developers for much better control over far-field related calculations and experiments. © 2017 Society of Photo-Optical Instrumentation Engineers (SPIE).

JAYEE SINHA

Electronic Science

T DAS

S SARKAR

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Aspect ratio-based formulation for far-field characterization of single-mode trapezoidal index fibers

Optical Engineering

Based on the splice loss analysis between two perfectly aligned single mode step and trapezoidal index fibers, we propose a simple empirical relation of power transmission coefficient in terms of normalised frequency and aspect ratio, using a recently reported Marcuse type formulation of spot size for trapezoidal index fiber. The relation is verified, after comparison with standard results from basic equations. Our empirical relation should find wide use by the system users to predict power transmission coefficient for known opto-geometrical parameters without the knowledge of spot size. Also, a simple graphical technique to predict an unknown aspect ratio of a trapezoidal index fiber is suggested and justified. © 2017 Elsevier GmbH

Optik

Prediction of power transmission coefficient and the aspect ratio of a single mode trapezoidal index fiber by using splice loss technique

We investigate the Kerr nonlinear optical processes (NOPs) in the case of a single-mode trapezoidal index fiber based on recently formulated and appropriate Marcuse-type relations for spot size in terms of normalized frequency corresponding to such fiber having various aspect ratios. With the help of these relations, we have analyzed the maximum NOP in these fibers having prospective the merits of tight light confinement in the subwavelength diameter waveguiding region. The comparative investigation reveals that the aspect ratio having a value of 0.7 is the most promising candidate for maximum optical nonlinearity, constructional convenience, and less diffraction. The analysis should be attractive for system users as a ready reference. © 2016 Society of Photo-Optical Instrumentation Engineers (SPIE).

Interesting effect of aspect ratio on Kerr nonlinear optical processes in subwavelength diameter single-mode trapezoidal index fiber using Marcuse-type spot-size formulations

Simple and complete empirical relations are presented here to determine a normalized spot size in terms of normalized frequencies over a long range and aspect ratio of a trapezoidal index single-mode fiber considering Gaussian approximation of the fundamental mode following the Marcuse method for the first time. After verification of their validity for arbitrary values of aspect ratio and normalized frequency, we calculate various propagation characteristics viz. dispersion and splice loss by using our formulations. Upon comparison, we observe an excellent match and the validity of our results with exact values and other results available in the literature. These formulas should attract the attention of experimentalists as a simple alternative to the rigorous methods of estimating the propagation characteristics of such fibers. © 2014 Society of Photo-Optical Instrumentation Engineers.

Journal	Data powered by TypesetOptical Engineering
Publisher	Data powered by TypesetSPIE
ISSN	0091-3286
Open Access	No