# Enhancing SPDC brightness using elliptical pump shapes

## TL;DR

This paper demonstrates that using elliptical pump shapes in SPDC significantly increases brightness, confirmed by experiments showing a twofold improvement over traditional circular modes, aligning with theoretical predictions.

## Contribution

The study introduces the use of elliptical pump modes to enhance SPDC brightness, providing experimental validation of theoretical models.

## Key findings

- Elliptical pump modes double the brightness compared to circular modes.
- Brightness enhancement depends on the ellipse's eccentricity and orientation.
- Experimental results confirm theoretical predictions about elliptical pump benefits.

## Abstract

We report on the use of elliptical pump spatial modes to increase the observed brightness of spontaneous parametric downconversion in critically phase matched crystals. Simulations qualitatively predict this improvement which depends on the eccentricity and orientation of the pump ellipse. We experimentally confirm a factor of two improvement in brightness when compared to the traditional circular-symmetric pump spatial modes. These results support previous theoretical work that proposes the use of elliptical pump modes to enhance the performance of parametric processes in anisotropic materials.