Written by Dom Siriani
Twenty-five years ago, Eli Yablonovitch wrote a remarkably influential journal letter on “Inhibited Spontaneous Emission in Solid-State Physics and Electronics” (Phys. Rev. Lett., 58, 2059, 1987). In this manuscript, he described how a periodic three-dimensional dielectric structure would produce an electromagnetic band gap that, when properly designed, could significantly reduce unwanted spontaneous emission in some of the most technologically fundamental electronic and photonic devices, viz. semiconductor lasers, bipolar transistors, and solar cells. What perhaps couldn’t be foreseen at the time is the remarkable innovation this paper would lead to, as the structure he described (which became known as a photonic crystal) turned into a focus of research for nearly everything related to controlling light.
The concept of a photonic crystal is hardly new; periodic dielectric structures were studied for at least a hundred years prior to Dr. Yablonovitch’s paper. In fact, one-dimensional photonic crystals were fairly widespread before 1987, perhaps the most notable example (or at least the one closest to my heart) being the distributed Bragg reflectors (DBRs) of vertical-cavity surface-emitting lasers (VCSELs). However, although the idea of the photonic crystal was well established, Dr. Yablonovitch brought to the forefront some very significant (and now just a few of many) important properties and applications of these structures.
A flurry of research followed. Scientists were able to demonstrate photonic crystals at microwave and optical frequencies, photonic crystal lasers, photonic crystal waveguides, high-quality-factor photonic crystal resonators, and the list goes on. And after many years of this commotion surrounding photonic crystals, they’ve even found a place in the commercial marketplace; it’s probably safe to say that just about everyone in the field of optics is aware of the photonic crystal fiber optics market.
So, with that background, I suppose I can come to the point. It’s pretty clear how appropriate it is for the Laser Science portion of FiO/LS to have invited a distinguished group of scientists to speak about the state of the art in photonic crystals (and you might also notice the term “photonic crystal” pop up in other invited talks). These presentations really seem to hit on some of the important applications (either established or promising) and studies of photonic crystals today: cavity QED, sensing (bio and other), nonlinear optics, silicon photonics, spectroscopy, and a number of devices (waveguides, lasers, etc.), just to name a few.
It’s very exciting to see what this seemingly brief history of intense photonic crystal research has led to. A lot has happened in the study and development of these structures over the past twenty-five years. I eagerly anticipate hearing some more review of this work. However, what’s even better is that it’s a certainty that I’ll learn something new about photonic crystals at the conference. I can’t wait to hear what remarkable new properties of these structures have been discovered and what innovative new applications have been found for them.
Disclaimer: Opinions, interpretations, conclusions, and recommendations are those of the author and are not necessarily endorsed by the United States Government and MIT Lincoln Laboratory.
Posted: 8/9/2012 6:41:10 PM by
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