Ultra-low-loss tapered optical fibers with minimal lengths

TL;DR

This paper presents the design and fabrication of ultra-low-loss tapered optical fibers with minimal lengths, achieving over 99.7% transmission in just 23 mm, through optimized taper shapes and fabrication methods.

Contribution

It introduces an optimized flame-brush fabrication process for ultra-low-loss tapered fibers with minimal lengths and compares their performance to other taper geometries.

Findings

Achieved over 99.7% transmission in 23 mm fibers.

Optimized taper shapes outperform constant taper angle fibers.

Fabrication method reduces fiber length while maintaining low loss.

Abstract

We design and fabricate ultra-low-loss tapered optical fibers (TOFs) with minimal lengths. We first optimize variations of the torch scan length using the flame-brush method for fabricating TOFs with taper angles that satisfy the adiabaticity criteria. We accordingly fabricate TOFs with optimal shapes and compare their transmission to TOFs with a constant taper angle and TOFs with an exponential shape. The highest transmission measured for TOFs with an optimal shape is in excess of 99.7 % with a total TOF length of only 23 mm, whereas TOFs with a constant taper angle of 2 mrad reach 99.6 % transmission for a 63 mm TOF length.