Ultrafast dynamics and spectral dependence of optical nonlinearities in doped semiconductors at epsilon-near-zero (Conference Presentation)

摘要: Materials where the real part of permittivity is near zero are known to have interesting nonlinear optical properties such as enhanced harmonic generation and large refraction (NLR). In particular, NLR highly doped semiconductors Indium Tin Oxide Aluminum Zinc in near-infrared spectral regions, crosses zero, precise wavelength which can be tuned by controlling doping level.. This also epsilon (ENZ) regime, although imaginary not necessarily small at this wavelength. order characterize these nonlinearities, we use Beam-Deflection (BD) method directly temporal dynamics polarization dependence nondegenerate absorption ENZ. BD has sensitivity induced path length 1/20,000 a wavelength, enables us resolve presence backgrounds. The technique allows separation instantaneous bound electronic nonlinearities from non-instantaneous mechanisms carrier redistribution effects that dominate ENZ materials,. We study on relative incidence angle excitation probe waves. Our reveals effect tuning or waves through separately find strong around point quite different for pump