Next Waves in Photonics

It’s been a year since I was involved in photonics and optics product development.  That year has given me the opportunity to follow advances in photonics more broadly — and learn about the newest work, which is always exciting.

There is a wave of amazing research in this area which will start getting commercialized in the next decade.  Perhaps there will be another market driver/marke bubble to hurry some of these R&D projects to market, as the optical communications boom did in the late 1990’s.  Don’t forget the groundwork for the boom (in particular laser diode and optical amplification advances) were laid years before.

One can speculate what that market driver will be: another wave in optical communications as we go to 100Gb links and “universal” fiber-to-the-premise?  advent of large (or small) 3D/”Minority Report”/curved/augmented reality displays everywhere?  imaging biosensors going mass-market to monitor personal health stats?  demand for ultra-efficient programmable lighting in work and home spaces?  image sensors with the capacity to provide us “Live/TiVo’able Google Street View” (and you thought we had privacy concerns now)?

I’ll let you speculate on that.  Let me review some of the technologies which might come into play as we get there (start with Wikipedia def’s):

  • Quantum dots.  Tiny particles that can be engineered to have wavelength-selective emission or absorption properties.  QD Array There are already many companies working with these.  Most simply they can be used like a phosphor to absorb light at one (higher energy) wavelength and emit at another — like Evident Technologies is doing (coming out of bankruptcy in 2009).  Local QD Vision (North Bridge, Highland, In-Q-Tel, DTE Energy Ventures) initially went after electrically-driven QD light emitters, but is also now focusing on phosphor-like products with their Quantum Light™ products.  On the detection side, Invisage (Rockport, Charles River Ventures, InterWest Partners) has a very ambitious plan to go after mass-market camera sensors.  Use of QD’s in “everyday” products like skin cream is proliferating as well — sometimes with bold claims; e.g. converting harmful UV rays into “therapeutic” wrinkle-removing light…
  • Organic Light Emitters (such as OLEDs) / Detectors.  OLEDs are finally a mass-market item, now that theOLED Windows Google Nexus One sports one for its (beautiful) main screen; though it is very difficult to imagine any technology taking on LCDs in mainstream displays until display requirements take a radical turn.  OSRAM (Siemens sub; sister co of OSRAM Sylvania which is hiring lots of engineers in Danvers to make regular LED lighting) has been demonstrating OLEDs for general lighting, which is interesting because one can (theoretically) make large panels.  One of the perennial issues with OLEDs has been encapsulation to keep out moisture and oxygen for long lifetime.  On the cutting-edge end, work continues on high-responsivity organic detectors (this one about work at the excellent UCSB group, drill down for paper).  And of course, as with every other light emitting material, you try to make it into a LASER! The latest advance from the group of Steve Forrest (UMich), a guy you often find at the forefront of optical materials and devices, is described here (there’s a Nature Photonics article for anyone who wants to dig more).
  • Surface Plasmon Resonance.  The use of patterned thin metallic films which couple radiation into the plane of the metal, very selectively; they effectively combine optical and electrical transport which makes them interesting.  SPR is used in commercial biosensors built by Sensata Technologies in Attleboro (NYSE:ST, former TI division taken private and IPO’d this year by Bain Capital).  Work in this area is being done in a number of labs including MIT’s Marin Soljacic (though he mainly does theory here), who is also behind Witricity, the MIT wireless power spin-off (not SPR, though it is resonant!).  Metal films with tiny holes to achieve interesting optical effects are being used by Pacific Biosciences (>$200M from Kleiner Perkins, Alloy, MDV and others ) to build next-generation gene sequencing equipment.  SPR devices being dreamed up remind me a little of the many photonic crystal devices which were postulated 10 years ago– they look great on paper, but since (as opposed to 1D layered thin film devices) they require lateral patterning, accurate fabrication is difficult, and your performance rapidly degrades.  So “averaging” over a large effective sample, and controlling that average in fabrication, is the way to go.
  • Negative Index Metamaterials.  Basically — structuring materials at a nano scale to make light bend backwards.  An awesome prospect in terms of building optics, as well as novel “invisibility cloaks” (here’s a nice explanation from UCB).  negative indexFor obvious reasons, most researchers are running after visible-light versions; however working with these “short” wavelengths requires fabricating really tiny structures.  I think there are many opportunities in longer wavelengths, including of course long-wavelength infrared (LWIR) where the cost of optics is still very high.  I’m also fascinated by the analogue of these materials and devices in the acoustic world; being able to build them would have great implications in medical (and industrial) ultrasound, and underwater mapping and communications.

I’ll cut my list there.  And those are only the “new” fields (not really new, just evolving quickly).  Skipped quantum entanglement for now– frankly I need to spend a couple of hours with a book to really get it, and the complexities.

There are of course all the devices that were developed in the last optical boom which are in the slow process of becoming “consumerized.”  The obvious example is in optical communications, with fiber systems spreading all the way to the home.  The less obvious, but I think very exciting (from the point of view of leveraging tech into business), applications are things like cosmetic photonic systems– using laser systems to remove wrinkles, hair, etc.  I was first introduced to that field when I met the CEO of SemiNex (Peabody), a group of ex-optical communications guys who is building low-cost, high-power laser diodes for these markets.  Some of the leaders in photonic cosmetic instruments are in MA as well: Palomar Medical (Nasdaq:PTMI, Burlington), Cynosure (Nasdaq:CYNO, Westford); and Gillette has had an on/off laser hair removal program as well.  But there is enough to write about in that area to justify another post…

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