2-photon ionization and necessary laser and vacuum systems for experiments with trapped strontium ions

TL;DR

This paper presents an efficient method for photoionizing strontium atoms using a two-photon process with a pulsed laser, along with detailed descriptions of the laser, vacuum, and ion trap systems for trapping Sr+ ions.

Contribution

It introduces a practical setup combining laser, vacuum, and trap systems for trapping and ionizing strontium ions in a linear RF trap, enabling repeatable ion chain experiments.

Findings

Successful trapping of linear Sr+ ion chains at UHV pressures

Use of a 2-photon process at 431nm for efficient ionization

Detailed design of laser and vacuum systems for quantum experiments

Abstract

We describe a efficient way to photoionize strontium atoms in a linear radio-frequency trap. We use a 2-photon second order process to excite the autoionization resonance (4d2 + 5p2) 1D2. A doubled pulsed Ti:Saphire laser system is used at 431nm to provide 100fsec pulses at 82Mhz. The fabrication of the laser systems for addressing the Sr+ transitions necessary for laser cooling and excitation of quantum jumps, vacuum system and ion trap structure are also described in detail. With the current setup a easy and repeatable trapping of linear ion chains is achieved at UHV pressures.