Nobel Prize shines light on optics, photonics past, present, future
November 18, 2014
Last month, the Nobel Prize in chemistry went to Eric Betzig, Stefan W. Hell and W.E. Moerner for discoveries that have transformed optical microscopy. Their accomplishments are a compelling story of innovative, brilliant work that carries imaging of microscopic objects beyond the limit imposed by diffraction of light. Along the way, it illustrates some of the opportunities that are emerging in both optics and photonics. Conventional optical imaging can resolve objects as small as the wavelength of light, a few hundred nanometers. The work of this year's laureates meets the challenge of "going beyond the diffraction limit" to even smaller objects.
A fundamental connection among the techniques that Betzig, Hell and Moerner invented is using laser light to manipulate molecules to emit on demand. The key to detecting light from individual molecules is to excite only a few of them. One way to accomplish this goal is to work with very dilute samples as Moerner first did with a small number of emitting molecules embedded in a sample of non-emitting molecules. These experiments began the era of "single molecule dynamics" where chemists could study matter one molecule at a time. However, there are many important samples, such as biological structures, where a host of emitters are near each other. Further manipulation of samples with light is the key to overcoming that problem.
Laser 'light switches'
A central aspect to these new microscopies is labeling the biomolecule with an efficient emitter such as a dye molecule or variant of green fluorescent protein (GFP). (GFP's discovery is another piece of NSF-funded, Nobel-winning basic research that has transformed fields in unimagined ways.) Using pulses of laser light to turn off most emitters in a sample reduces the number of potential targets to a very few, making the sample artificially dilute. Repeating that process many times with different emitters turned on builds up an image with previously unobtainable resolution, as the accompanying picture from the Nobel website illustrates.
The techniques that earned the Nobel Prize this year point to the power of modern optics. Producing exotic wavelengths from relatively modest laboratory lasers and observing processes on timescales as fast as an electron's motion are illustrations of new frontiers that optical science is exploring. The intimately related, rapidly growing field of photonics is also central to this revolution. Recognizing that optics is the manipulation of light to tailor its interaction with matter and that photonics is the manipulation of matter to tailor its interaction with light reveals their close connection.
The excitement and promise in 'light' science
Optics and photonics are apt designations for an intellectual space that promises both near- and long-term rewards. Though not brand new, the confluence of fundamental and practical advances makes optics and photonics a particularly attractive opportunity now. More than 15 years ago, a report from the National Academies, Harnessing Light: Optical Science and Engineering for the 21st Century, emphasized fundamental opportunities. In 2012, another report, Optics and Photonics: Essential Technologies for Our Nation, pointed to many practical opportunities awaiting realization. Even more recently, in 2014, a National Science and Technology Council working group identified interagency connections and opportunities in this area. All of these efforts, along with work by organizations such as the Optical Society of America, have identified and articulated a collection of opportunities.
NSF has a long history of supporting research in optics and photonics as well as projects that use them as research tools, and now we are looking to expand that effort. In July, the Directorates for Mathematical and Physical Sciences (MPS), Engineering (ENG), and Computer and Information Science and Engineering (CISE) published a Dear Colleague Letter (DCL) highlighting just two of the areas that are ready for increased attention: light-matter interactions at the nanoscale and novel terabit communication systems. We hope these areas are just a start.
The confluence of intellectual opportunity and an enthusiastic research community can open doors to new directions. It is our responsibility at NSF to respond to those opportunities and nurture them, a process that involves persuasion and advocacy on many fronts.
I look forward to sharing more news periodically and welcome your emailed comments at: mpsperspective@nsf.gov
Dr. F. Fleming Crim
NSF Assistant Director for Mathematical and Physical Sciences
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