Multiplex frequency conversion of unamplified 30-fs Ti: sapphire laser pulses by an array of waveguiding wires in a random-hole microstructure fiber.

An array of fused silica waveguiding channels with randomly distributed transverse sizes in a disordered microstructure fiber is shown to allow a highly efficient broadly tunable frequency conversion of low-energy ultrashort laser pulses. Dispersion can be switched in such waveguide arrays by coupling the pump field into waveguiding wires with different diameters. Microstructure-fiber-integrated random arrays of waveguides with diameters ranging from 0.6 up to 1.5 mum can frequency-convert unamplified subnanojoule Ti: sapphire laser pulses with an initial duration of 30 fs to any wavelength within a broad spectral range from 400 up to 700 nm, suggesting interesting fiber-optic strategies for multiplex frequency conversion and sensing.