Trapping atoms in the evanescent field of laser written wave guides

TL;DR

This paper demonstrates a method to trap atoms near laser written waveguides using a two-color evanescent field, optimizing parameters to reduce losses and enable stable atom trapping on integrated optical chips.

Contribution

It introduces a novel two-color trapping scheme for atoms near waveguides, overcoming limitations of single-mode traps and providing a practical approach for atom-chip integration.

Findings

Stable two-color traps can be created with specific waveguide modes.

Optimized parameters significantly reduce photon scattering and tunneling losses.

The scheme is feasible with current experimental technology.

Abstract

We analyze evanescent fields of laser written waveguides and show that they can be used to trap atoms close to the surface of an integrated optical atom chip. In contrast to subwavelength nanofibres it is generally not possible to create a stable trapping potential using only the fundamental modes. This is why we create a stable trapping potential by using two different laser colors, such that the waveguide supports two modes for the blue detuned laser, while for the red detuned light the waveguide has only a single mode. In particular, we study such a two-color trap for Cesium atoms, and calculate both the potential and losses for the set of parameters that are within experimental reach. We also optimize system parameters in order to minimize trap losses due to photon scattering and tunneling to the surface.