Enhanced eumelanin emission by stepwise three-photon excitation

Josef Kerimo; Milind Rajadhyaksha; Charles A. DiMarzio

doi:10.1117/12.873598

28 February 2011 Enhanced eumelanin emission by stepwise three-photon excitation

Josef Kerimo, Milind Rajadhyaksha, Charles A. DiMarzio

Proceedings Volume 7903, Multiphoton Microscopy in the Biomedical Sciences XI; 79031X (2011) https://doi.org/10.1117/12.873598
Event: SPIE BiOS, 2011, San Francisco, California, United States

Abstract

Eumelanin fluorescence from Sepia officinalis and black human hair was activated with near-infrared radiation and multiphoton excitation. A third order multiphoton absorption by a step-wise process appears to be the underlying mechanism. The activation was caused by a photochemical process since it could not be reproduced by simple heating. Both fluorescence and brightfield imaging indicate the near-infrared irradiation caused photodamage to the eumelanin and the activated emission originated from the photodamaged region. At least two different components with about thousand-fold enhanced fluorescence were activated and could be distinguished by their excitation properties. One component was excited with wavelengths in the visible region and exhibited linear absorption dependence. The second component could be excited with near-infrared wavelengths and had a third order dependence on the laser power. The third order dependence is explained by a step-wise excited state absorption (ESA) process since it could be observed equally with the CW and femtosecond lasers. The new method for photoactivating the eumelanin fluorescence was used to map the melanin content in human hair.

Citation Download Citation

Josef Kerimo, Milind Rajadhyaksha, and Charles A. DiMarzio "Enhanced eumelanin emission by stepwise three-photon excitation", Proc. SPIE 7903, Multiphoton Microscopy in the Biomedical Sciences XI, 79031X (28 February 2011); https://doi.org/10.1117/12.873598

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available