Self-phase modulation in single CdTe nanowires.

ABSTRACT

We measure the transmission of near-infrared ps pulses through single CdTe nanowires. Benefitting from the strong light confinement and large effective nonlinearity of these nanowires, a significant spectral broadening of ∼ 5 nm and nonlinear phase shift of a few π due to self-phase modulation (SPM) is observed experimentally at coupled peak power of a dozen W with a propagating length down to several hundred µms. A nonlinear-index coefficient (n2) as high as (9.5 ± 1.4) × 10-17 m2/W at 1550 nm is extracted from transmission spectra, corresponding to a nonlinear parameter (γ) of ∼ 1050 W-1m-1. The simulations indicate a spectral broadening more than 1.5 µm in single nanowire when pumped by fs pulses in anomalous dispersion regime. The obtained results suggest that, CdTe nanowire is promising in developing ultracompact nonlinear optical devices for microphotonic circuits.