Effect of the interference in overlapped double-pulse irradiation at the silicon surface

TL;DR

This study investigates how interference effects in overlapped double-pulse laser irradiation influence silicon excitation, revealing that constructive interference enhances efficiency while destructive interference reduces it, with potential doubling of excitation efficiency.

Contribution

The paper introduces a combined three-temperature model and Maxwell's equations approach to analyze interference effects in double-pulse laser irradiation on silicon surface.

Findings

Constructive interference significantly increases lattice temperature and absorbed energy.

Destructive interference reduces laser excitation efficiency.

Overlapped double pulses can double the excitation efficiency compared to separate pulses.

Abstract

We studied the excitation process of silicon under an intense double pulse. We employed the three-temperature (electron, hole, and lattice) model (3TM) together with Maxwell's equations. We solved Maxwell's equations by the finite-difference time-domain approach. The lattice temperature and absorbed energy at the surface increase significantly when the two laser pulses overlap with constructive interference. On the other hand, destructive interference substantially reduces the efficiency of laser excitation. On average, the overlapped double pulse increases the efficiency to about twice the distinct two-pulse case.