Dispersion measurement method with down conversion process

TL;DR

This paper introduces a novel method for characterizing the dispersion of nonlinear crystals using phase matching in parametric down conversion, enabling dispersion measurement across a broad spectrum with a single spectrometer.

Contribution

The authors present a new technique for dispersion measurement of nonlinear materials utilizing phase matching in parametric down conversion, demonstrated on a periodically poled potassium titanyl phosphate crystal.

Findings

Effective dispersion characterization from 390 to 1800 nm.

Single spectrometer used for UV-visible range measurement.

Method applicable to various nonlinear crystals.

Abstract

Proper characterization of nonlinear crystals is essential for designing single photon sources. We show a technique for dispersion characterization of a nonlinear material by making use of phase matching in the process of parametric down conversion. Our method is demonstrated on an exemplary periodically poled potassium titanyl phosphate $KTiOPO_4$ crystal phase-matched for $396$ nm to $532$ nm and $1550$ nm. We show a procedure to characterize the dispersion in the range of $390$ to $1800$ nm by means of only one spectrometer for the UV-visible range.