# Full spatiotemporal control of laser-excited periodic surface deformations

## TL;DR

This paper presents a method for precisely controlling surface deformations at nanoscales in space and time using independent optical transient grating excitations, enabling potential manipulation of material properties.

## Contribution

It introduces an experimental setup for independent control of spatial and temporal phases of optical excitations to manipulate surface deformations at sub-nanosecond and micrometer scales.

## Key findings

- Demonstrated control of surface deformations via optical phase manipulation.
- Experimental validation with x-ray reflectivity measurements.
- Potential applications in tailoring material properties through strain fields.

## Abstract

We demonstrate full control of acoustic and thermal periodic deformations at solid surfaces down to sub-nanosecond time scales and few-micrometer length scales via independent variation of the temporal and spatial phase of two optical transient grating (TG) excitations. For this purpose, we introduce an experimental setup that exerts control of the spatial phase of subsequent time-delayed TG excitations depending on their polarization state. Specific exemplary coherent control cases are discussed theoretically and corresponding experimental data are presented in which time-resolved x-ray reflectivity measures the spatiotemporal surface distortion of nanolayered heterostructures. Finally, we discuss examples where the application of our method may enable the control of functional material properties via tailored spatiotemporal strain fields.