Kieu Khanh, Mansuripur Masud
College of Optical Sciences, The University of Arizona, Tucson, Arizona 85721, USA.
Opt Lett. 2008 Jan 1;33(1):64-6. doi: 10.1364/ol.33.000064.
We report the design and operation of a novel all-fiber bidirectional passively mode-locked ring laser. An erbium-doped fiber was chosen as the active element in a ring cavity arrangement. A short segment of a fiber taper embedded in carbon nanotubes/polymer composite, acting as a saturable absorber, was used to enable bidirectional mode locking. The laser generates two stable femtosecond pulse trains in opposite directions. A beat note of about 2 MHz, having a bandwidth of less than 2 kHz, is measured when the pulses propagating in opposite directions are (temporally) overlapped at a photodetector. We believe this device will find important applications in precision rotation sensing.
