Efficient fiber-optical interface for nanophotonic devices

TL;DR

This paper presents a highly efficient method for coupling light from single-mode optical fibers to nanophotonic devices using tapered fibers, achieving up to 97% efficiency, suitable for integrated photonics and sensing.

Contribution

Introduces a novel adiabatic tapering technique for fiber-to-nanophotonic device coupling with record efficiency levels.

Findings

Achieved coupling efficiencies up to 97%

Demonstrated compatibility with various device geometries

Enabled potential applications in quantum optics and sensing

Abstract

We demonstrate a method for efficient coupling of guided light from a single mode optical fiber to nanophotonic devices. Our approach makes use of single-sided conical tapered optical fibers that are evanescently coupled over the last ~10 um to a nanophotonic waveguide. By means of adiabatic mode transfer using a properly chosen taper, single-mode fiber-waveguide coupling efficiencies as high as 97(1)% are achieved. Efficient coupling is obtained for a wide range of device geometries which are either singly-clamped on a chip or attached to the fiber, demonstrating a promising approach for integrated nanophotonic circuits, quantum optical and nanoscale sensing applications.