Luis Orozco, APS Distinguished Traveling Lecturer: Optical nanofibers & some experiments in optomechanics

Optical nanofibers are produced by gradually reducing an ordinary single-mode optical fiber to half-micron diameters, less than the typical wavelength of light that we use at 780 nm. A propagating electric field induces a torque in the nanofiber depending on the angle between the birefringent axis of the fiber and the electric field. We have studied the optomechanical coupling of light and the torsional mode of one of these nanofibers. We have observed significant changes, both decrease and increase, in the thermal noise of the fundamental torsional mode depending on the angle of polarization with respect to the birefringence axes of the nanofiber. We measure the thermal noise reductions with the Maxwell-Boltzmann distribution of amplitude fluctuations and show cooling by three orders of magnitude from room temperature when using feedback in the cooling process.