Frequency conversion of abruptly autofocusing waves

TL;DR

This paper explores the nonlinear frequency conversion of abruptly autofocusing waves, specifically ring-Airy beams, through sum-frequency generation, analyzing how different interaction conditions affect their autofocusing behavior.

Contribution

It provides the first systematic experimental study on nonlinear frequency conversion of abruptly autofocusing waves, offering guidelines for creating frequency interfaces for such waves.

Findings

Successful frequency conversion of ring-Airy beams demonstrated

Interaction location and pump structure significantly influence autofocusing behavior

Provides a general framework for nonlinear transformation of autofocusing waves

Abstract

Abruptly autofocusing waves and associated ring-Airy (RA) beams are attracting increasing interest owing to their fascinating properties such as their ability of abruptly autofocusing to small F-number. Optical frequency conversion via nonlinear interactions can further expand their applications to new area, yet are rarely studied. In this work, we report the frequency conversion of RA beams via sum-frequency generation using perfect flattop and common Gauss beams as the pump beams. The nonlinear transformation of the spatial complex amplitude of the signal and associated influences on autofocusing behavior, under different conditions of interaction location (i.e., original, autofocusing, and Fourier planes) and pump structure, were systematically studied and experimentally investigated. This proof-of principle demonstration provides a general guideline to build the frequency interface for abruptly autofocusing waves and a reference for relevant studies involving nonlinear transformation of abruptly autofocusing waves.