Evaluation of a femtosecond fiber laser for two-photon fluorescence correlation spectroscopy

✍ Scribed by Jay R. Unruh; E. Shane Price; Roque G. Molla; Rongqing Hui; Carey K. Johnson

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 99 KB
• Volume: 69
• Category: Article
• ISSN: 1059-910X
• DOI: 10.1002/jemt.20358

✦ Synopsis

Abstract

This work evaluates a femtosecond fiber laser for use in two‐photon fluorescence fluctuation spectroscopy. Fiber lasers present an attractive alternative to Ti:Sapphire systems because of their compact size and portability. Autocorrelation of the second harmonic generation signal from the laser demonstrates that its stability is sufficient for two‐photon fluorescence correlation spectroscopy. Fluorescence correlation spectroscopy autocorrelation traces were well fit by a Gaussian–Lorentzian squared model with a beam waist near the diffraction limit for the 810 nm wavelength. A photon counting histogram collected with this system also fit nicely to a single‐species model, further demonstrating the quality of the focal shape. The authors conclude that the output from the femtosecond fiber laser is sufficiently stable and has a high enough quality beam shape for fluctuation fluorescence methods, and thus represents an effective, compact, readily portable two‐photon excitation source. Microsc. Res. Tech., 2006. © 2006 Wiley‐Liss, Inc.