Supercontinuum generation in submicrometer diameter silica fibers

Area of Science:

• Photonics
• Optical Nanostructures
• Nonlinear Optics

Background:

• Silica nanowires offer strong mode confinement for studying nonlinear pulse propagation.
• Tapered silica fibers are model systems for investigating light-matter interactions.

Purpose of the Study:

• To investigate the effect of fiber diameter on supercontinuum generation in silica fiber tapers.
• To identify optimal parameters for generating coherent white-light sources using tapered fibers.

Main Methods:

• Fabrication of silica fiber tapers with diameters ranging from 200 nm to 1200 nm.
• Generation of supercontinuum using femtosecond laser pulses.
• Analysis of spectral broadening and its dependence on fiber diameter, dispersion, and nonlinearity.

Main Results:

• Observed strong diameter-dependence in supercontinuum spectral broadening.
• Identified diameter-dependent dispersion and nonlinearity as key factors.
• Demonstrated low energy threshold (approx. 1 nJ) for supercontinuum generation.

Conclusions:

• Tapered silica fibers exhibit significant diameter-dependent nonlinear optical properties.
• Fibers with diameters between 400-800 nm are ideal for efficient supercontinuum generation.
• These tapered fibers serve as excellent nanophotonic sources for coherent white-light generation.