New platform developed to measure and exploit optomechanical interactions

December 13, 2012
New platform developed to measure and exploit optomechanical interactions
A pair of nanobeams is held side-by-side and separated by a nanoscale gap, with one beam supporting a mechanical mode, and the other supporting a confined optical mode. The properties of the optical mode of the beam on the left are concentrated in the nanoscale gap in-between the beams, ensuring a strong radiation pressure interaction with the mechanical mode in the beam on the right. The platform enables nearly independent design of the optics and the mechanics.

(Phys.org)—Researchers from the NIST Center for Nanoscale Science and Technology and Caltech have developed a new design platform for measuring and exploiting strong interactions between light confined in a nanoscale structure and an adjacent nanomechanical system. The versatile platform opens new approaches for fabricating sensitive light detectors and for converting wavelengths for use in quantum information science. Previously, the Caltech team used silicon "optomechanical crystals" in which radiation pressure from light drove mechanical vibrations within a single, doubly-clamped silicon nanobeam. In the new work, the CNST-Caltech collaborators developed a design for observing similar effects in silicon nitride, which has a much broader optical transparency window than silicon, but for which radiation pressure interactions within a single nanobeam are expected to be much weaker.

The new approach uses a pair of nanobeams held side-by-side and separated by a nanoscale gap, with one beam supporting a mechanical mode which has a specific vibration pattern and frequency, and the other supporting a confined optical mode which has a specific spatial field distribution and optical frequency. Crucially, while the properties of the optical mode are largely controlled by only one of the two beams, it is concentrated in the small region in-between the beams, ensuring that the radiation pressure interaction with the mechanical mode in the other beam is strong. Electromagnetic simulations show that the optomechanical interaction strength increased by nearly a factor of three relative to the single beam case.

An important aspect of the new platform is that it enables near-independent design of the optics and the mechanics, so a wide range of new functionalities may be possible. In particular, the team is working on geometries in which two optical beams operating at widely different wavelengths are coupled to a mechanical beam held in-between them. Such devices are expected to enable wideband optical-to-optical and even microwave-to-optical frequency conversion, which would be significant advances in this field.

Explore further: Technological breakthrough in Silicon Photonics: Intel Silicon-based Optical Modulator Could Run Faster Than 1GHz

More information: Davanço, M. et al., Slot-mode-coupled optomechanical crystals, Optics Express 20, 24394–24410 (2012).

Related Stories

Nanoscale zipper cavity responds to single photons of light

June 4, 2009

Physicists at the California Institute of Technology have developed a nanoscale device that can be used for force detection, optical communication, and more. The device exploits the mechanical properties of light to create ...

Laser light used to cool object to quantum ground state

October 5, 2011

For the first time, researchers at the California Institute of Technology (Caltech), in collaboration with a team from the University of Vienna, have managed to cool a miniature mechanical object to its lowest possible energy ...

Recommended for you

Algorithm ensures that random numbers are truly random

June 24, 2016

(Phys.org)—Generating a sequence of random numbers may be more difficult than it sounds. Although the numbers may appear random, how do you know for sure that they don't actually follow some complex, underlying pattern? ...

Possibility of new particle discovery at LHC fading

June 24, 2016

The physics community is apparently starting to lose its buzz over the possibility of the discovery of a new particle by researchers working at the CERN LHC facility near Geneva. As more data is studied, it appears more and ...

Important milestone reached on road to a redefined kilogram

June 21, 2016

In a secure vault in the suburbs of Paris, an egg-sized cylinder of metal sits in a climate-controlled room under three glass bell jars. It is the mass against which all other masses in the world are measured - by definition ...

Probing giant planets' dark hydrogen

June 23, 2016

Hydrogen is the most-abundant element in the universe. It's also the simplest—sporting only a single electron in each atom. But that simplicity is deceptive, because there is still so much we have to learn about hydrogen.

Why planes freeze

June 21, 2016

Pilots and safety officials worry about ice accumulating on the wings and tail of an aircraft flying during freezing rain. Abnormal ice buildup can disturb airflow to alter the physics of flight and lead to stalls, rolls ...

0 comments

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.