A new physical mechanism allows 'phonon lasing' driven by optical forces at ambient conditions

October 28, 2015 by Icn2, Catalan Institute of Nanoscience and Nanotechnology
(A) SEM micrograph of the OM photonic crystal cavity. (B) Normalized transmission spectrum around the studied optical mode for input laser powers of 5 μW and 1 mW (black and red curves respectively). The threshold for establishing the regime of self-sustained oscillation is indicated (green dashed vertical line). (C) Transduced acoustic modes up to 200 MHz. The red dots correspond to the go,OM/2π values of the in-plane flexural eigenmodes as predicted by FEM simulations. The OM photonic crystal deformation profiles associated to the first three odd in-plane flexural modes are also illustrated. Credit: Scientific Reports article (Fig 1)

Recent years have seen a steady increase in the number of research reports dealing with full control of phonons. The word "phononics" is slowly entering the scientific vocabulary to indicate a platform in which coherent phonons can be generated, harnessed and detected. In the field of photonics, lasers were a key element to fully enable the technology, but development was not achieved until lasers became easy to build and control. Likewise, despite the so-called "phonon laser" that has been demonstrated in several publications, the high device quality (narrow linewidth) and strict experimental demands of vacuum and low temperature necessary for observable effects or potential applications make it too complex a source for a rapid implementation. 

A work recently published in Nature's Scientific Reports, headed by the Phononic and Photonic Nanostructures Group led by ICREA Prof. Clivia M. Sotomayor-Torres and with Dr. Daniel Navarro-Urrios as its first author, reports "phonon lasing" in a one-dimensional opto-mechanical crystal in response to an anharmonic modulation of the intracavity radiation pressure force.

The latter is a consequence of spontaneous triggering in the optical cavity of a self-pulsing regime, i.e., a stable dynamic competition between thermo-optic (TO) effects and free-carrier-dispersion (FCA). The feedback exerted by the coherent mechanical oscillations on the self-pulsing makes the coupled system a frequency-entrained, self-stabilized oscillator. The wide dynamical frequency tuning of the self-pulsing enables a manifold of frequency-entrained regions associated to the coherent amplification of different mechanical modes up to hundreds of MHz. The self-pulsing dynamics could be readily engineered, enabling the scaling of the phonon lasing frequency up to the tens of GHz. 

Commonly, the phonon lasing regime in optomechanical systems is achieved by means of dynamical back-action. In this case, compensating intrinsic mechanical losses demands restrictive conditions, and the requirements for the optical and mechanical modes in terms of quality factors and inter-coupling strengths are not easy to fulfill. Our findings show a new physical mechanism that allows phonon lasing under far more relaxed configurations; moreover, this opens new research avenues in the field of non-linear opto-mechanics. The system operates at ambient conditions of pressure and temperature in a silicon platform, which enables its exploitation in sensing, intra-chip metrology or time-keeping applications. 

Explore further: An optomechanical crystal to study interactions among colocalized photons and phonons

More information: D. Navarro-Urrios et al. A self-stabilized coherent phonon source driven by optical forces, Scientific Reports (2015). DOI: 10.1038/srep15733

Related Stories

Researchers build fully mechanical phonon laser

March 19, 2013

(Phys.org) —Researchers working at Japan's NTT Basic Research Laboratories have successfully built an all mechanical phonon laser. In their paper published in Physical Review Letters, the team describes how they built a ...

Controllable mode competition in a phonon laser

November 20, 2013

Using a novel realization of a "phonon laser," scientists at PML and the Joint Quantum Institute (JQI) have observed and learned to control a process called mode competition. This process occurs routinely in optical lasers, ...

Quantum leap for phonon lasers

February 22, 2010

Physicists have taken major step forward in the development of practical phonon lasers, which emit sound in much the same way that optical lasers emit light. The development should lead to new, high-resolution imaging devices ...

Controlling acoustic transport in hypersonic crystals

October 27, 2014

Center for Nanoscale Materials users from Toyota Research Institute of North America, working with CNM's Nanophotonics Group, have determined that bulk coherent acoustic vibrations are heavily damped by scattering from radially ...

Recommended for you

Coffee-based colloids for direct solar absorption

March 22, 2019

Solar energy is one of the most promising resources to help reduce fossil fuel consumption and mitigate greenhouse gas emissions to power a sustainable future. Devices presently in use to convert solar energy into thermal ...

Physicists reveal why matter dominates universe

March 21, 2019

Physicists in the College of Arts and Sciences at Syracuse University have confirmed that matter and antimatter decay differently for elementary particles containing charmed quarks.

ATLAS experiment observes light scattering off light

March 20, 2019

Light-by-light scattering is a very rare phenomenon in which two photons interact, producing another pair of photons. This process was among the earliest predictions of quantum electrodynamics (QED), the quantum theory of ...

How heavy elements come about in the universe

March 19, 2019

Heavy elements are produced during stellar explosion or on the surfaces of neutron stars through the capture of hydrogen nuclei (protons). This occurs at extremely high temperatures, but at relatively low energies. An international ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.