Research Papers

Two-color, two-photon, and excited-state absorption microscopy

[+] Author Affiliations
Dan Fu

Princeton University, Department of Chemistry, Princeton, New Jersey 08544

Tong Ye, Thomas E. Matthews

Duke University, Department of Chemistry, Durham, North Carolina 27708

Gunay Yurtsever

Duke University, Department of Biomedical Engineering, Durham, North Carolina 27708

Warren S. Warren

Duke University, Department of Chemistry and Radiology, Durham, North Carolina 27708

J. Biomed. Opt. 12(5), 054004 (September 17, 2007). doi:10.1117/1.2780173
History: Received November 08, 2006; Revised March 18, 2007; Accepted May 12, 2007; Published September 17, 2007
Text Size: A A A

We develop a new approach in imaging nonfluorescent species with two-color two-photon and excited state absorption microscopy. If one of two synchronized mode-locked pulse trains at different colors is intensity modulated, the modulation transfers to the other pulse train when nonlinear absorption takes places in the medium. We can easily measure 106 absorption changes caused by either two-photon absorption or excited-state absorption with a RF lock-in amplifier. Sepia melanin is studied in detail as a model system. Spectroscopy studies on the instantaneous two-photon absorption (TPA) and the relatively long-lived excited-state absorption (ESA) of melanin are carried out in solution, and imaging capability is demonstrated in B16 cells. It is found that sepia melanin exhibits two distinct excited states with different lifetimes (one at 3ps, one lasting hundreds of nanoseconds) when pumped at 775nm. Its characteristic TPA/ESA enables us to image its distribution in cell samples with high resolution comparable to two-photon fluorescence microscopy (TPFM). This new technique could potentially provide valuable information in diagnosing melanoma.

Figures in this Article
© 2007 Society of Photo-Optical Instrumentation Engineers


Absorption ; Photons


Dan Fu ; Tong Ye ; Thomas E. Matthews ; Gunay Yurtsever and Warren S. Warren
"Two-color, two-photon, and excited-state absorption microscopy", J. Biomed. Opt. 12(5), 054004 (September 17, 2007). ;


Access This Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

PubMed Articles
Cerenkov specific contrast agents for detection of pH in vivo. J Nucl Med Published online Feb 5, 2015.;
Noise evaluation of Compton camera imaging for proton therapy. Phys Med Biol Published online Feb 6, 2015.;
  • Don't have an account?
  • Subscribe to the SPIE Digital Library
  • Create a FREE account to sign up for Digital Library content alerts and gain access to institutional subscriptions remotely.
Access This Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).
Access This Proceeding
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
Access This Chapter

Access to SPIE eBooks is limited to subscribing institutions and is not available as part of a personal subscription. Print or electronic versions of individual SPIE books may be purchased via