Research & Development World

  • R&D World Home
  • Topics
    • Aerospace
    • Automotive
    • Biotech
    • Careers
    • Chemistry
    • Environment
    • Energy
    • Life Science
    • Material Science
    • R&D Management
    • Physics
  • Technology
    • 3D Printing
    • A.I./Robotics
    • Software
    • Battery Technology
    • Controlled Environments
      • Cleanrooms
      • Graphene
      • Lasers
      • Regulations/Standards
      • Sensors
    • Imaging
    • Nanotechnology
    • Scientific Computing
      • Big Data
      • HPC/Supercomputing
      • Informatics
      • Security
    • Semiconductors
  • R&D Market Pulse
  • R&D 100
    • Call for Nominations: The 2025 R&D 100 Awards
    • R&D 100 Awards Event
    • R&D 100 Submissions
    • Winner Archive
    • Explore the 2024 R&D 100 award winners and finalists
  • Resources
    • Research Reports
    • Digital Issues
    • R&D Index
    • Subscribe
    • Video
    • Webinars
  • Global Funding Forecast
  • Top Labs
  • Advertise
  • SUBSCRIBE

Terahertz Laser Pulses Intensify Optical Phonons in Solids

By Max Planck Institute For The Science Of Human History | November 15, 2018

When light excites the material and induces large atomic vibrations at frequency ω (blue wave), fundamental material properties are modulated in time at twice such frequency (red wave), acting a source for phonon amplification. © Jörg Harms/MPSD

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the amplification of optical phonons in a solid by intense terahertz laser pulses.

These light bursts excite atomic vibrations to very large amplitudes, where their response to the driving electric field becomes nonlinear and conventional description fails to predict their behavior.

In this new realm, fundamental material properties usually considered constant are modulated in time and act as a source for phonon amplification.

The paper, “Parametric Amplification of Optical Phonons” by Andrea Cartella et al., has been published in the PNAS.

The amplification of light dramatically changed science and technology in the 20th century. This path, which began in 1960 with the invention of the laser, still has such a remarkable impact that the 2018 Nobel Prize in Physics was awarded “for groundbreaking inventions in the field of laser physics.” Indeed, the amplification of other fundamental excitations like phonons or magnons is likely to have an equally transformative impact on modern condensed matter physics and technology.

The group led by Cavalleri at the MPSD has pioneered the field of controlling materials by driving atomic vibrations (i.e. phonons) with intense terahertz laser pulses. If the atoms vibrate strongly enough, their displacement affects material properties. This approach has proven successful in controlling magnetism, as well as inducing superconductivity and insulator-to-metal transitions.

In this field, it is then important to understand whether the phonon excitation by light can be amplified, potentially leading to performative improvements of the aforementioned material control mechanisms.

In the present work, Cartella, Cavalleri, and coworkers used intense terahertz pulses to resonantly drive large-amplitude phonon oscillations in silicon carbide and investigated the dynamic response of this phonon by measuring the reflection of weak (also resonant) probe pulses as a function of time delay after the excitation.

“We discovered that for large enough intensities of our driving pulses, the intensity of the reflected probe light was higher than that impinging on the sample,” says Cartella.

“As such, silicon carbide acts as an amplifier for the probe pulses. Because the reflectivity at this frequency is the result of the atomic vibrations, this represents a fingerprint of phonon amplification.”

The scientists were able to rationalize their findings with a theoretical model that allowed them to identify the microscopic mechanism of this phonon amplification: fundamental material properties, usually considered constant, are modulated in time and act as a source for amplification. This is the phononic counterpart of a well-known nonlinear optical effect, the so-called four-wave-mixing.

These findings build upon another discovery by the Hamburg group that was published earlier this year, showing that phonons can have a response reminiscent of the high-order harmonic generation of light. These new discoveries suggest the existence of a broader set of analogies between phonons and photons, paving the way for the realization of phononic devices.

This work was supported by the ERC Synergy Grant “Frontiers in Quantum Materials’ Control” (Q-MAC). The Center for Free-Electron Laser Science (CFEL) is a joint enterprise of DESY, the Max Planck Society and the University of Hamburg. This collaboration involved also Professor Roberto Merlin of the University of Michigan.

Source: Max Planck Institute for the Structure and Dynamics of Matter

Related Articles Read More >

Illustration of ultracold atoms (gold) flowing frictionlessly along a laser boundary (green), representing the quantum phenomenon of edge states.
MIT physicists directly observe frictionless ‘edge state’ flow in ultracold atoms, offering a glimpse of super-efficient electronics
NTT Research scientist in cleanroom suit working on advanced photonic equipment
NTT Research bets light-based computing can tackles AI’s energy crisis
Scientists claim to generate world’s strongest terahertz radiation
SLAC fires up the world’s most powerful X-ray laser: LCLS-II ushers in a new era of science
rd newsletter
EXPAND YOUR KNOWLEDGE AND STAY CONNECTED
Get the latest info on technologies, trends, and strategies in Research & Development.
RD 25 Power Index

R&D World Digital Issues

Fall 2024 issue

Browse the most current issue of R&D World and back issues in an easy to use high quality format. Clip, share and download with the leading R&D magazine today.

Research & Development World
  • Subscribe to R&D World Magazine
  • Enews Sign Up
  • Contact Us
  • About Us
  • Drug Discovery & Development
  • Pharmaceutical Processing
  • Global Funding Forecast

Copyright © 2025 WTWH Media LLC. All Rights Reserved. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media
Privacy Policy | Advertising | About Us

Search R&D World

  • R&D World Home
  • Topics
    • Aerospace
    • Automotive
    • Biotech
    • Careers
    • Chemistry
    • Environment
    • Energy
    • Life Science
    • Material Science
    • R&D Management
    • Physics
  • Technology
    • 3D Printing
    • A.I./Robotics
    • Software
    • Battery Technology
    • Controlled Environments
      • Cleanrooms
      • Graphene
      • Lasers
      • Regulations/Standards
      • Sensors
    • Imaging
    • Nanotechnology
    • Scientific Computing
      • Big Data
      • HPC/Supercomputing
      • Informatics
      • Security
    • Semiconductors
  • R&D Market Pulse
  • R&D 100
    • Call for Nominations: The 2025 R&D 100 Awards
    • R&D 100 Awards Event
    • R&D 100 Submissions
    • Winner Archive
    • Explore the 2024 R&D 100 award winners and finalists
  • Resources
    • Research Reports
    • Digital Issues
    • R&D Index
    • Subscribe
    • Video
    • Webinars
  • Global Funding Forecast
  • Top Labs
  • Advertise
  • SUBSCRIBE