Effect of misalignment on coupling efficiency in laser diode to single-mode circular core graded-index fiber coupling via cylindrical microlens on the fiber tip

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Biplab Kumar Ray ◽  
Mithun Maity ◽  
Sankar Gangopadhyay ◽  
Anup Kumar Maiti
Keyword(s):  
Laser Diode ◽  
Coupling Efficiency ◽  
Vertical Plane ◽  
Poor Performance ◽  
Single Mode ◽  
Potential Candidate ◽  
Gaussian Field ◽  
Fiber Coupling ◽  
Graded Index ◽  
User Friendly

Abstract We report here the first theoretical prediction of coupling efficiency of the laser diode to single-mode graded-index fiber coupling via cylindrical microlens on the tip of the fiber in presence of possible transverse and angular mismatches. Moderately efficient cylindrical microlens on the fiber is easily fabricable and graded-index fiber has less sensitivity to macro as well as micro bending. Thus this coupling device emerges as a potential candidate in the field of coupling optics. The analysis takes into consideration the allowable aperture provided by cylindrical microlens. Further, we shall consider here the coupling in the vertical plane only since the coupling in the horizontal plane has poor performance. Using the relevant ABCD matrix of refraction for a cylindrical lens in the vertical plane, we prescribe analytical expressions of the coupling efficiencies in presence of said kinds of misalignments. In our analysis, we use Gaussian field distribution for both the laser and fiber fields. We carry on our investigation for two commonly used wavelengths namely 1.3 and 1.5 µm. As an example of graded-index fiber, we use some typical step, parabolic, and triangular index fibers in our study. The execution of the prescribed formulations involves little computation. Thus the evaluation of the concerned coupling efficiencies is very much user friendly. The present analysis surfaces the tolerance factors of the coupling devices. Accordingly, the results will prove beneficial to designers and packagers in respect of the design of such coupler involving cylindrical microlens in the field of optimum launch optics.

Laser diode to single-mode graded index fiber coupling via cylindrical microlens on the fiber tip: evaluation of coupling efficiency by ABCD matrix formalism

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Kushal Roy ◽  
Angshuman Majumdar ◽  
Shubhendu Maiti ◽  
Sankar Gangopadhyay
Keyword(s):  
Laser Diode ◽  
Coupling Efficiency ◽  
Vertical Plane ◽  
Poor Performance ◽  
Single Mode ◽  
Matrix Formalism ◽  
Abcd Matrix ◽  
Graded Index ◽  
Analytic Expressions ◽  
Realistic Prediction

AbstractWe use ABCD matrix formalism for estimation of the coupling optics involving laser diode to cylindrical lensed circular core graded index fiber excitation. The investigation has been carried on for some typical step, parabolic, and triangular index fibers as examples of graded index fiber. It is relevant to mention in this connection that we have shown that the coupling optics is excellent along the vertical plane only while the coupling along the horizontal plane produces poor performance. Analytic expressions for coupling efficiencies are prescribed. The investigations have been made for two commonly used wavelengths, namely 1.3 and 1.5 µm. Our formulations require little computation for the necessary execution. The wavelength of 1.3 µm has been found to be more efficient in respect of coupling. Our formalism takes care of the limited aperture allowed by the cylindrical lens and thus provides the realistic prediction of coupling optics. The results will prove extremely useful to the designers and packagers working with cylindrical microlens.

Single-mode fiber coupling efficiency with graded-index rod lenses

1994 ◽  
Vol 33 (16) ◽  
pp. 3440 ◽  
Author(s):  
Robert W. Gilsdorf ◽  
Joseph C. Palais
Keyword(s):  
Coupling Efficiency ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Fiber Coupling ◽  
Graded Index

A Simple Method for Prediction of Effective Core Area and Index of Refraction of Single-mode Graded Index Fiber in the Low V Region

2014 ◽  
Vol 35 (4) ◽  
Author(s):  
Angshuman Majumdar ◽  
Satabdi Das ◽  
Sankar Gangopadhyay
Keyword(s):  
Refractive Index ◽  
Single Mode ◽  
Index Of Refraction ◽  
Core Area ◽  
Exact Results ◽  
Simple Method ◽  
Graded Index ◽  
Core Areas ◽  
V Region ◽  
User Friendly

AbstractBased on the simple power series formulation of fundamental mode developed by Chebyshev formalism in the low V region, we prescribe analytical expression for effective core area of graded index fiber. Taking step and parabolic index fibers as examples, we estimate the effective core areas as well as effective refractive index for different normalized frequencies (V number) having low values. We also show that our estimations match excellently with the available exact results. The concerned predictions by our method require little computation. Thus, this simple but accurate formalism will be user friendly for the system engineers.

Study on Coupling of Step and Graded Index Single Mode Optical Fiber Considering the Transverse Misalignment

2020 ◽  
Vol 8 (2) ◽  
pp. 78-82
Author(s):  
Prosenjit Roy Chowdhury ◽  
◽  
Keyword(s):  
Optical Fiber ◽  
Communication Systems ◽  
Structural Parameters ◽  
Fractional Power ◽  
Single Mode ◽  
Spot Size ◽  
Fiber Coupling ◽  
Fundamental Parameters ◽  
Graded Index ◽  
Wide Range

"Advance design and day to day up-gradation of communication system is the requirement of international telecommunication. The optical communication systems involve the effective fiber coupling or splicing to meet the need of long communication channel. When the studies on both the intensive and extensive properties of optical fiber are exploring new research horizons, the effectiveness of such systems can be calibrated with transmission parameters like transmitted fractional power, which is a function of ‘spot size’ as well. Our study of fiber junctions based on fundamental parameters like wavelength, fiber profile index etc. has touched some unrevealed areas and explored some interesting results. The profile index of optical fiber has received less attention compared to other structural parameters of optical fiber but our study at important wavelengths for different profiles has shown that the less-used fiber profiles has some interesting premier outcomes, which can introduce some significant impact on optical fiber based system design and engineering. We have observed almost frequency or wavelength independent transmitted fractional power around the most used 1.55 micrometer wavelengths at some rarely used fiber profile index. Our study predicts the best and worst fiber profiles for transmitted fractional power (T ), at the same time, we have observed the fiber profile index independent region for a band of ‘T’ values. The reporting and its approach are found to be premier in this field. So, our work is reporting a comparison of effective fiber-to-fiber coupling, based on fiber profile index of different fibers. It is also giving a clear view of the wavelength dependency of effective fiber coupling for different fibers having wide range of graded fiber profiles."

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