Second harmonic generation (SHG) has been developed in our laboratories as a high-resolution nonlinear optical imaging microscopy for cellular membranes and intact tissues. SHG shares many of the advantageous features for microscopy of another more established nonlinear optical technique: two-photon excited fluorescence (TPEF). Both are capable of optical sectioning to produce threedimensional images of thick specimens and both result in less photodamage to living tissue than confocal microscopy. SHG is complementary to TPEF in that it uses a different contrast mechanism and is most easily detected in the transmitted light optical path. It can be used to image membrane probes with high membrane specificity and displays extraordinary sensitivity in reporting membrane potential; it also has the ability to image highly ordered structural proteins without any exogenous labels.


Originally published in Journal of Biomedical Optics, July 2001, Vol. 6, No. 3 - J. Biomed. Opt. 6, 277 (2001). DOI:10.1117/1.1383294


two-photon excitation, membrane potential, gold nanoparticles, fluorescence lifetime, collagen

Subject Categories

Second harmonic generation, Nonlinear optics


Bioimaging and biomedical optics | Nanoscience and Nanotechnology



Publication Date


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Copyright 2001 One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.

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Society of Photo-Optical Instrumentation Engineers

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