Jonathan Cave Knight

Bragg scattering from an obliquely illuminated photonic crystal fiber

Scattering at visible frequencies from a two-dimensional silica/air photonic crystal material in the form of a fine fiber reveals the hexagonal crystal structure of the material. Oblique illumination allows the observation of first-order Bragg conditions even for a crystal structure with a pitch several times the wavelength of light. These scattering measurements demonstrate the feasibility of a low-loss waveguide based on photonic bandgap effects.

Scalar modulation instability near zero GVD using a PCF

Scalar modulation instability has been demonstrated in the normal dispersion regime using a PCF leading to efficient upconversion of a red pump to wavelengths throughout the visible.

Supercontinuum Generation and Soliton Timing Jitter in SF6 Photonic Crystal Fibers

Using XFROG and FROG we observe the details of supercontinuum formation and soliton dynamics in highly-nonlinear SF6 photonic crystal fibers. At high input powers in the anomalous dispersion region the solitons display substantial temporal jitter.

Femtosecond pulse propagation dynamics near second zero-dispersion point in photonic crystal fibers

Cross-correlation frequency-resolved optical gating is used to probe the dynamics of a femtosecond pulse in a double-zero dispersion point photonic crystal fiber. Soliton attraction to the second zero-dispersion point and multiple-soliton interaction are observed.

Generation of spectrally distinct third harmonic in photonic crystal fibers

By coupling femtosecond pulses at λ=1.55 microns in a one meter segment of photonic crystal fiber we observe simultaneous generation of third harmonic frequencies from both the fundamental and its self-shifted Raman component, whereas no second harmonic signal is detected.

Photonic crystals as optical fibers - properties and applications

Photonic crystal fiber is a pure silica fiber with a regular array of air holes running down its length. We describe band-gap and effective-index waveguiding in these structures, and the remarkable new properties they possess.