Polarization-Controlled Nonlinear Computer-Generated Holography

TL;DR

This paper introduces a novel method for dynamic nonlinear beam shaping using polarization control and type II phase matching, enabling arbitrary intensity distribution control in frequency-converted fields with high efficiency.

Contribution

It presents the first experimental demonstration of polarization-controlled nonlinear holography using type II phase matching for dynamic beam shaping.

Findings

Arbitrary intensity distributions achieved in frequency-converted fields.

Conversion efficiencies comparable to linear beam shaping.

Potential for UV spectral range beam shaping.

Abstract

Dynamic phase-only beam shaping with a liquid crystal spatial light modulator is a powerful technique for tailoring the beam's intensity profile or wave front. While shaping and controlling the light field is a highly researched topic, dynamic nonlinear beam shaping has hardly been explored so far. One potential reason is that generating the second harmonic is a degenerate process as it mixes two fields at the same frequency. To overcome this problem, we propose the use of type II phase matching as a control mechanism to distinguish the two involved fields. We experimentally demonstrate that arbitrary intensity distributions can be shaped in the frequency-converted field at the same quality as for linear beam shaping and with conversion efficiencies similar to the case without beam shaping. We envision this technique as a milestone towards beam shaping beyond the physical limits of liquid crystal displays, i.e. facilitating dynamic phase-only beam shaping in the ultraviolet spectral range.