Abstract
Nanostructured gratings in a metal surface can highly enhance nonlinear optical processes. The geometrical parameters that characterize a grating can be optimized to achieve intense near-fields, which in turn enhance the nonlinear optical signals. For a nonlinear process that involves multiple frequencies, like four-wave mixing (FWM), the optimization of grating parameters necessary to enhance the radiation in-coupling for both frequencies is not trivial. Here, we propose, compute, and experimentally demonstrate a grating design that is resonant to two excitation frequencies and thus enhances the frequency mixing processes more efficiently. Second- and third-order nonlinear mechanisms are studied using two spatially and temporally overlapped laser pulses with different frequencies. Using our grating design, we achieve an unprecedented nonlinear FWM enhancement factor of 7 × 10 3.
Original language | English |
---|---|
Article number | 101101 |
Journal | Applied Physics Letters |
Volume | 116 |
Issue number | 10 |
DOIs | |
Publication status | Published - 9 Mar 2020 |
Externally published | Yes |
Funding
We thank Thomas Bauer and Irina Komen for their assistance in the fabrication of nanostructured gold films. This work is part of the research program of the Netherlands Organization for Scientific Research (NWO). The authors acknowledge funding from the European Research Council (ERC Advanced Grant No. 340438-CONSTANS).
Funders | Funder number |
---|---|
Netherlands Organization for Scientific Research | |
European Research Council | 340438-CONSTANS |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek |