Colloquia

Communication systems leverage the respective strengths of optics and electronics to convey high-bandwidth signals over great distances.  These systems were enabled by a revolution in low-optical-loss dielectric fiber, complex integrated circuits as well as devices that link together the optical and electrical worlds.  Today, another revolution is leveraging the advantages of optics and electronics in new ways.  At its center is the laser frequency comb which provides a coherent link between these two worlds. Significantly, because the link is also bidirectional, performance attributes previously unique to electronics and optics can be shared. The end result has been transformative for time keeping, frequency metrology, precision spectroscopy, microwave-generation, ranging and other technologies. Even more recently, low-optical-loss dielectrics, now in the form of high-Q optical resonators, are enabling the miniaturization of frequency combs. These new `microcombs’ can be integrated with electronics and other optical components to potentially create systems on-a-chip.  I will briefly overview the history and elements of frequency combs as well as the physics of the new microcombs. Application of the microcombs for spectroscopy and LIDAR will be discussed.  Finally, efforts underway to develop integrated optical clocks and integrated optical frequency synthesizers using the microcomb element are described.