Interaction of Intense Mid-Infrared Laser Pulses with Nanostructured Metasurfaces: Coulomb Explosion
Abstract
Interaction of intense laser pulses with nanostructured surfaces is of great scientific interest because it involves several fundame,ntal processes in laser-matter interaction: local concentration and resonant enhancement of optical energy density, rapid accelerati,on and expulsion of electrons from judiciously designed solid targets, generation of high harmonics, and many others. Many practical, applications are also easy to envision, such as novel approaches to nanoscale fabrication, efficient multi-photon conversion, and g,eneration of exotic broadband non-Gaussian radiation pulses. Of particular interest and complexity is the high-intensity (non-therma,l) interaction between mid-infrared (MIR) laser pulses and dielectric/semiconductor metasurfaces. High-Q metasurfaces can concentrat,e light to high energy density that translates into large kinetic energy of laser-produced electrons. A wide range of novel nonlinea,r phenomena, from harmonic generation to metasurface charging and Coulomb explosion, is enabled by the free energy available to the,released electron.Building upon my groups expertise in the fields of metasurfaces, plasma physics, and nonlinear optics, I propose,a comprehensive program to investigate the physics of nonlinear laser-metasurface interactions in both non-destructive and destructi,ve regimes. The proposed research is separated into two Focus Areas, each consisting of three Tasks. The specific objectives and del,iverables of this project are:Focus Area 1: To develop a new concept of a Pre-Fabricated Coulomb-Exploding (PREFACE) metasurface tha,t will use the combination of fabricated metasurfaces and laser-generated free carriers to produce exquisite nanometer-scale feature,s. While most metasurfaces are designed to maximize the intensity of concentrated infrared energy, this project will u,phisticated particle-tracking and first- principles particle-in-cell (PIC) codes that estimate the ejected electron charge, and calc,ulate ion explosionof the resulting charge-imbalanced structures. These theoretical results will be used to design new and optimized, metasurfaces, and to qualitatively interpret the existing and forthcoming experimental results. This will enable us to reverse-eng,ineer the field enhancement and localization in the hot spots of the exploded PREFACE nanostructures. Novel diagnostics of the rapi,d electron-hole generation at the hotspots of the PREFACE metasurfaces based on second and third harmonics generation will be develo,ped and used to for experimental validation of the predicted plasma conditions that lead to Coulomb Explosions.Focus Area 2: To deve,lop a novel diagnostic of high-intensity laser-metasurface interaction based on high-harmonics generation from Non-Stationary Nonlin,ear (NOSNO) metasurfaces illuminated by judiciously engineered MIR laser pulses. Such diagnostic will enable us to answer several fu,ndamental questions that arise when an intense pulse interacts with a high-Q metasurface: (i) what is the optimal shape of the laser, pulse that enables the highest field intensities inside NOSNO metasurfaces? (ii) Can laser-matter interaction be controlled using t,he phase of the MIR laser pulse, in addition to its intensity? (iii) What is the importance of the rapid change of NOSNO metasurface,s during the interaction? (iv)What are the benefits of using a second near-infrared laser pulse to enhance the interactions of the M,IR pulse with the metasurface? Experiments will be carried out in the destructive and in non-destructive regimes using chirped laser, pulse with durations ranging from 100fs to several picoseconds.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 05, 2022
- Source ID
- N000142212199
Entities
People
- Gennady Shvets
Organizations
- Cornell University
- Office of Naval Research
- United States Navy