Biomedical subjects
Publications and source records attributed to Philip St J Russell.
We study the spatiotemporal dynamics of ultrashort pulses close to a point of zero group-velocity dispersion in planar waveguides with focusing nonlinearities. We find that the process of pulse collapse enhances the emission of so-called resonant radiation, providing an efficient mechanism of energy transfer from solitonic to dispersive waves and leading to suppression of the collapse.
Working with complex guiding structures such as holey fibers requires coupling light into the input face of the structure. We use a simple in vivo technique to determine the scale, morphology, and orientation of the input cleave of the fiber without resorting to separate and more complex methods like optical imaging or scanning electron microscopy. Further, after obtaining the transverse scan of the fiber tip one can precisely position the focal spot anywhere relative to the fiber structure.
Modulation instability at high frequencies has been demonstrated in the normal dispersion regime by use of a photonic crystal fiber. This fiber-optic parametric generator provides efficient conversion of red pump light into blue and near-infrared light.