Coupling of modes in bent biconically tapered single-mode fibers

Author

Shankar, P.M. ; Bobb, Lloyd C. ; Krumboltz, Howard D.

Author_Institution

Dept. of Electr. & Comput. Eng., Drexel Univ., Philadelphia, PA, USA

Volume

9

Issue

7

fYear

1991

fDate

7/1/1991 12:00:00 AM

Firstpage

832

Lastpage

837

Abstract

Biconically tapered single-mode fibers are fabricated by heating a single-mode fiber while applying tension. As a result of this tapering, cladding modes are excited in the tapered region of the fiber where the V parameter of the fiber goes down below 1.0. These cladding modes couple to one another, leading to fluctuations of the optical throughput. Since the index difference between the cladding and the external medium is rather high (~0.5), the cladding modes will be of the exact type, namely, TE, TM, HE, and EH modes. The coupling of these modes in the tapered region is analyzed using the exact mode formalism when the tapered region is bent. The theoretical results agree very well with experimental results obtained on bent tapers which show strong fluctuations of the optical power as a function of the bending angle

Keywords

optical fibres; V parameter; bending angle; bent biconically tapered single-mode fibers; cladding modes; exact mode formalism; external medium; index difference; optical power; optical throughput; tapered region; tension; transverse electric modes; transverse magnetic modes; Fluctuations; Heating; Helium; Optical coupling; Optical fiber couplers; Optical fiber sensors; Optical fiber theory; Optical sensors; Tellurium; Throughput;

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/50.85782

Filename

85782