Brian Washburn

Brian R. Washburn


Kansas State University

Monday, September 28, 2009

4:00 p.m.

Cardwell 102


Holey Fibers & Nanotubes!

Advances for Fiber Lasers & Fiber Laser-Based Frequency Combs


Photonic crystal fibers have made a substantial impact in optics, specifically for nonlinear fiber optics, laser physics, and optical frequency metrology.  In this colloquium, I will discuss how we implement hollow-core photonic crystal fibers for novel fiber laser and fiber amplifier design.  I will introduce a mode-locked fiber laser that uses carbon nanotubes for a saturable absorber, which we have phase stabilized this laser for the first time.  We also developed a novel parabolic amplifier that uses a low-dispersion-slope photonic crystal fiber in order to produce near transform-limited sub-33 fs pulses.  These pulses were used to generate the supercontinuum needed for phase stabilization of the carbon nanotube fiber laser.  To investigate the stability of the comb produced by this fiber laser, we mixed it against a continuous-wave laser stabilized to an acetylene-filled photonic crystal fiber reference.  These measurements resulted in an upper limit on the comb’s instability of 1.2 x 10-11 in 1 s.  Finally, I discuss our work on a new class of continuous wave lasers that will be made through the amalgamation of hollow fiber and optically pumped gas technologies.  This laser will have a molecular gas lasing medium in a photonic crystal fiber so it will have the advantages of a gas laser with a cavity compatible with optical fiber technology.