Dr Nicolas Olivier
Department: Physics & Astronomy
Phone: +44 (0)114 222 3582
The parallel developments of fluorescent proteins  and fluorescence microscopy has revolutionized our understanding of biological systems by allowing researchers to follow in real time at the sub-micron scale specific proteins tagged with a fluorescent protein in live cells. The different physical properties of fluorescent light (wavelength, lifetime, polarization, temporal fluctuations, emission pattern…) can all be used to recover information about the position and environment (chemical, optical, but also mechanical) of the fluorescent molecules and can therefore provide additional information about the structure of interest.
In the lab, we both use and develop new microscopy methods. On the microscopy side, we focus on new super-resolution microscopy methods based on single molecule localization  by focusing on the photophysics of the dyes  and on the physical properties of the light emitted . On the application side, we focus on the nanoscale organisation of the centrosome , a small organelle that controls the cytoskeleton of cells.
 Tsien, R. Y. Angewandte Chemie 48.31 (2009) - Shimomura, O. Angewandte Chemie 48.31 (2009) Chalfie, M. Angewandte Chemie 48.31 (2009)
 Rust, M. et al. Nature Methods 3.10 (2006) - Betzig, E. et al. Science 313.5793 (2006) - Hess, S. et al. Biophysical Journal 91.11 (2006)
 Olivier, N. et al. PloS one 8.7 (2013): e69004. - Olivier, N., et al. Biomedical Optics Express 4.6 (2013)
 Bourg, N. et al. Nature Photonics 9,587–593 (2015)
 Gönczy, P. Nature Reviews Molecular Cell Biology 13.7 (2012) - Keller, D. et al. The Journal of Cell Biology 204.5 (2014)
Tissue imaging is limited by the poor optical properties of biological tissues, with scattering and absorption resulting in a loss of both signal and contrast as imaging depth increases. Nonlinear imaging relies on nonlinear optical phenomena that occur when the light intensity is very high (such as when a femtosecond laser is focused tightly) and where multiple photons can interact with the same molecule. In particular, two-photon excited fluorescence is possible, and allows fluorescence imaging much deeper into samples . Moreover, coherent nonlinear processes such as second harmonic generation and third harmonic generation are also possible within tissues, and provide intrinsic contrast that can be used to reconstruct 3D images of unstained samples such as embryos . The contrast mechanisms of these methods are non-trivial and depend on interferences within the focal volume , and can therefore be controlled by shaping the pulses . Our aim is to investigate the potential of phase and polarization shaping to multi-beam processes, in particular to improve the resolution deep inside complex biological tissues
 Denk, W. et al. Science 248.4951 (1990)
 Olivier, N. et al. Science 329.5994 (2010)
 Barad, Y. et al. Applied Physics Letters 70.8 (1997)
 Olivier, N. et al. Optics Express 20.22 (2012) - Masihzadeh, O. et al. Optics Letters 34.8 (2009).