New Optomechanical Crystal Allows Confinement of Light and Sound 91
PBH writes "Physicists and engineers at the California Institute of Technology (Caltech) have developed a nanoscale crystal that traps both light and sound. The interaction of light quanta (photons) and sound quanta (phomons) are so strong that they produce significant mechanical vibrations. 'Indeed, Painter points out, the interactions between sound and light in this device—dubbed an optomechanical crystal—can result in mechanical vibrations with frequencies as high as tens of gigahertz, or 10 billion cycles per second. Being able to achieve such frequencies, he explains, gives these devices the ability to send large amounts of information, and opens up a wide array of potential applications—everything from lightwave communication systems to biosensors capable of detecting (or weighing) a single macromolecule. It could also, Painter says, be used as a research tool by scientists studying nanomechanics. "These structures would give a mass sensitivity that would rival conventional nanoelectromechanical systems because light in these structures is more sensitive to motion than a conventional electrical system is."'"
Could this be related? (Score:2, Interesting)
Re:Could this be related? (Score:3, Interesting)
Well, one can dream anyway.
Add an electret or piezoelectric bit... (Score:3, Interesting)
...and maybe have a new kind of microwave antenna?
Phonons (Score:1, Interesting)
I don't see how this is news. The concept of optical and acoustic phonons has been around for at least the past 50 years. It's long been understood that optical and acoustic phonons exist in periodic potential crystal lattices. It's also been long understood that you can excite both optical and acoustic phonons using optical photons. This is the premise behind coherent raman scattering, which has long been observed. The article makes it seem like this is the first time this concept has ever been discovered.
It really annoys me when "prestigious" university professors publish crap like this. They make it sound like they've discovered some new amazing phenomenon and prey on the public's lack of understanding of physics to get a nice pat on the back, and perhaps a fat paycheck, from university bigwigs who like having their institution linked with these "discoveries". About once a year, some professor tells the world he has transmitted information at faster-than-light speeds, and everyone buys it, but it always comes down to group velocity - a concept discovered and understood over a century ago.
Better Audio Speakers, Mics, Ultrasound, Sonar? (Score:4, Interesting)
If you have such fine control over vibrations, perhaps you could create fancier waveforms, for sound that has weird properties. Phased array sonar?
Constructive and destructive interference?
I own a pair of Bose noise-canceling headphones that I enjoy, so maybe that tech would be enhanced by these crystals. Or perhaps you could make sonic weapons by building up massive disruptor wave pulses
I'm trying to think of what high frequency synchrotron radiation makes possible through EM. The extremly short wavelengths allow imaging of very tiny objects like molecules. So would extremely short mechanical wavelengths allow extremely fine sonic imaging of... individual cells?
Re:Better Audio Speakers, Mics, Ultrasound, Sonar? (Score:4, Interesting)
I was thinking more along the lines of communication data. Crystals of this sort could be placed on either end of a pipe, and translate the data into and from ultra high frequency. Essentially working like a switch. If the data travels well in those frequencies, I could see massive potential in communications.
I also see storage potential here as well.
help me with this (Score:3, Interesting)
Am I the first to be dazzled by this?
When electron tubes gave way to transistors I sensed a revolution in progress, but it was hard to wrap my brain around a simple transistor being able to do such a variety of things with such a small energy cost.
Now this. My now aged brain struggles to comprehend and see the implications. I expect all to be revealed in this forum.
Re:Add an electret or piezoelectric bit... (Score:3, Interesting)
> Well the confined optical mode is 200THz so an RF EM mode wouldn't be
> confined and therefore wouldn't overlap effectively with the vibronic modes
> in the nano-structure.
Right. It would be radiated. That's the idea.
> I also really doubt that inducing vibrations in the nano-structure would
> generate an optical (or other EM) field.
The idea is to convert the GHz vibrations into an oscillating electric field. Thus the piezo material (or perhaps electret).
Science fiction story parallel - "slow glass" (Score:3, Interesting)
Re:Not a fundamentally new idea (Score:3, Interesting)
This is different than acousto-optics. There is no outside force here; all the movement is generated by the light itself. The miniscule amount of force from the light is enough to excite a resonance in the mechanical structure. The structure is both resonant to light and to acoustics. The two resonances are coupled because as the structure moves, the optical resonance shifts a little bit.
It is really cool work, but I haven't figured out what it'll be useful for.
Re:Science fiction story parallel - "slow glass" (Score:1, Interesting)
I remember that book! He called it the piezoluctic effect.
Re:Phonon, not phomon (Score:3, Interesting)
I'm having trouble wrapping my head around this, despite (or because of?) a class I took in college in the late 70s. Photons I understand; light has characteristics of both waves and particles. That was covered in the class. However, phonons? Sound is simply the vibration of matter. There are no "subatomic sound particles". Where there is no matter there is no sound, unlike light. The vibration of an object IS sound. Nowhere in the wikipedia article about phonons does it say what they actually ARE and why modern physics says they're necessary.
Can anybody shed any light on this?