Two-photon fluorescence imaging with 30 fs laser system tunable around 1 micron

Abstract

Abstract:We developed a low-cost, low-noise, tunable, high-peak-power, ultrafast laser system based on a SESAM-modelocked, solid-state Yb tungstate laser plus spectral broadening via a microstructured fiber followed by pulse compression. The spectral selection, tuning, and pulse compression are performed with a simple prism compressor. The output pulses are tunable from 800 to 1250 nm, with the pulse duration down to 25 fs, and average output power up to 150 mW, at 80 MHz pulse repetition rate. We introduce the figure of merit (FOM) for the two-photon and multiphoton imaging (or other nonlinear processes), which is a useful guideline in discussions and for designing the lasers for an improved microscopy signal. Using a 40 MHz pulse repetition rate laser system, with twice lower FOM, we obtained high signal-to-noise ratio two-photon fluorescence images with or without averaging, of mouse intestine section and zebra fish embryo. The obtained images demonstrate that the developed system is capable of nonlinear (TPE, SHG) imaging in a multimodal operation. The system could be potentially used in a variety of other techniques including, THG, CARS and applications such as nanosurgery. 1119-1121 (2000). 9. F. Druon, F. Balembois, and P. Georges, "New materials for short-pulse amplifiers," IEEE Photon. J. 3(2), 268-273 (2011). 10. S. Ricaud, A. Jaffres, K. Wentsch, A. Suganuma, B. Viana, P. Loiseau, B. Weichelt, M. Abdou-Ahmed, A. Voss, T. Graf, D. Rytz, C. Hönninger, E. Mottay, P. Georges, and F. Druon, "Femtosecond Yb:CaGdAlO4 thin-disk oscillator," Opt. Lett. 37(19), 3984-3986 (2012 Matuschek, and J. Aus der Au, "Semiconductor saturable absorber mirrors (SESAMs) for femtosecond to nanosecond pulse generation in solid-state lasers," IEEE ©2014 Optical Society of America