Quantum Optics Seminar by John R. Lawall

Photonic crystal mirrors, optomechanical bistability, and active-cavity optomechanics

We are developing mirrors that employ a photonic crystal slab, designed for ultrahigh optical reflectivity, fabricated in a defect in a phononic crystal, designed to minimize mechanical losses.  Using our most recent photonic crystals as end mirrors for Fabry-Perot cavities, we have achieved a record high finesse of F = 35,000.  The finesse is in fact so high that the cavity spectra exhibit strong optomechanical bistability and strong self-oscillation, even at atmospheric pressure.  In separate work, we have demonstrated that a laser is capable of self-cooling its own output coupler, a feat which had been thought to be impossible.  At present we are able to cool the fundamental mechanical mode from room temperature to an effective temperature of about 30 K, limited by the mechanical quality factor of the InP output coupler.  By using the photonic/phononic crystal mirrors that we are developing, it should be possible to improve the cooling by many orders of magnitude.

National Institute of Standards and Technology, Gaithersburg, MD