Ultra-low loss single-mode silica tapers manufactured by a microheater

TL;DR

This paper demonstrates a reproducible method for fabricating ultra-low loss, single-mode silica tapers using a ceramic thermoelectric heater, achieving high transmission efficiency and precise control over taper profiles for advanced optical applications.

Contribution

The authors introduce a novel, highly reproducible fabrication process for silica tapers with ultra-low loss using a microheater, enabling better control and performance.

Findings

Average taper transmission of 94%

Best tapers exceed 99% transmission

Taper profile closely follows theoretical exponential model

Abstract

Using a ceramic thermoelectric heater, we show highly reproducible fabrication of single-mode sub-wavelength silica tapers with ultra-low loss level. The reproducibility of the process is studied statistically, leading to an average taper transmission of 94%. The best tapers have a transmission superior to 99%, above common level reached by other fabrication methods. The taper profile is inspected along its length and closely follows the exponential profile predicted by the model of Birks and Li. This high degree of control over the taper shape allows a detailed analysis of the transition to the single-mode regime during tapering. As an application of this fabrication method, we present a micro-looped taper probe for evanescent coupling experiments requiring fine spatial selectivity.