# Efficient $2^3S$ positronium production by stimulated decay from the $3^3P$ level

## TL;DR

This paper demonstrates a method to significantly enhance the production of $2^3S$ positronium atoms by stimulating the decay from the $3^3P$ level using a broadband IR laser, surpassing natural spontaneous decay limitations.

## Contribution

The study introduces an experimental technique to increase $2^3S$ positronium production via stimulated decay, achieving over three times the spontaneous decay efficiency.

## Key findings

- Maximum relative increase of 3.1 times in $2^3S$ production.
- Optimal IR laser pulse intensity for stimulation identified.
- Enhanced positronium production surpasses natural spontaneous decay rates.

## Abstract

We investigate experimentally the possibility of enhancing the production of $2^3S$ positronium atoms by driving the $1^3S$-$3^3P$ and $3^3P$-$2^3S$ transitions, overcoming the natural branching ratio limitation of spontaneous decay from $3^3P$ to $2^3S$. The decay of $3^3P$ positronium atoms towards the $2^3S$ level has been effciently stimulated by a 1312.2nm broadband IR laser pulse. The dependence of the stimulating transition efficiency on the intensity of the IR pulse has been measured to find the optimal enhancement conditions. A maximum relative increase of $ \times (3.1 \pm 1.0) $ in the $2^3S$ production efficiency, with respect to the case where only spontaneous decay is present, was obtained.