We propose to use low-coherence-length cw optical sources with a broad spectrum in heterodyne near-field scanning microscopy in order to imitate optical pulse propagation and to obtain information about spectrally variant properties of nanophotonic components. The dispersion difference in the interferometer arms for a symmetric acousto-optic modulator arrangement is shown to be negligible over appreciable bandwidths. Demonstration of the principle of operation and viability of this approach is provided by measurement of the group refractive index of a silicon channel waveguide.
© 2009 Optical Society of America
Original Manuscript: December 2, 2008
Revised Manuscript: March 2, 2009
Manuscript Accepted: March 31, 2009
Published: April 20, 2009
Maxim Abashin, Kazuhiro Ikeda, Robert Saperstein, and Yeshaiahu Fainman, "Heterodyne near-field scanning optical microscopy with spectrally broad sources," Opt. Lett. 34, 1327-1329 (2009)