We report a new spectroscopic technique to measure simultaneously the intensity and the phase of second-harmonic (SH) radiation over a broad spectral range without laser tuning. Temporally separated SH pulses from two sources, excited by the same broad-bandwidth 15-fs Ti:sapphire fundamental pulse, interfere in a spectrometer to yield frequency-domain interference fringes. We demonstrate the technique by measuring the strongly bias-dependent phase of SH radiation from a Si/SiO<sub>2</sub>/Cr metal-oxide-semiconductor capacitor in the spectral range of the Si<i>E</i><sub>1</sub> critical point.
© 1999 Optical Society of America
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
(190.4350) Nonlinear optics : Nonlinear optics at surfaces
(190.4720) Nonlinear optics : Optical nonlinearities of condensed matter
(190.7110) Nonlinear optics : Ultrafast nonlinear optics
(240.6490) Optics at surfaces : Spectroscopy, surface
P. T. Wilson, Y. Jiang, O. A. Aktsipetrov, E. D. Mishina, and M. C. Downer, "Frequency-domain interferometric second-harmonic spectroscopy," Opt. Lett. 24, 496-498 (1999)