Images

Figure 2:
Imaging of 40 nm fluorescent microspheres (yellow-green fluorescent Fluo-Spheres carboxylate-modified microspheres, Invitrogen, Carlsbad, CA, USA).
The images were acquired sequentially using the internal APD (avalanche photodiode) detector, 32 lines averaging, 700 Hz per line, with a pixel size of 23 nm and pixel dwell time of 1.4 μs.
(a) and (b) were one-photon excited at 488 nm and acquired in the 500-550 nm spectral range using a pinhole size of 0.8 airy unit.
(c) and (d) were two-photon excited at 750 nm and acquired in the 500-550 nm spectral range using a pinhole size of 2 Airy unit.
In the STED mode (b and d), the 592 nm CW laser beam was superimposed at a typical power of 350 mW at the sample.
The scale bars are 1 μm [10].

From: Two-Photon Excitation for Optical Nanoscopy and Light-Sheet Illumination Microscopy
Alberto Diaspro,1,2 Paolo Bianchini,1 Francesca Cella-Zanacchi,1 Benjamin Harke,1 Michela Perrone,1 Emiliano Ronzitti,1 Silvia Galiani,1,2 Jenu Chacko,1,2 and Zeno Lavagnino.1,2 1. IIT – Istituto Italiano di Tecnologia, Genoa, Italy. 2. LAMBS MicroSCoBio, Department of Physics, University of Genoa, Italy.
Microscopy and Analysis 25(5):13-17 (AM), 2011