Adaptive optics & focus shaping

Sensorless 3D mapping of optical aberrations in thick samples. Adapted from Zeng et al, BOE 2012.

Nonlinear microscopy provides 3D images of biological tissues down to depths of several 100s of microns. Several contrast mechanisms can be used to obtain complementary information (e.g. 2P, 3P, SHG, THG). These nonlinear signals strongly depend on the spatial distribution of the focused field (amplitude, phase, polarization). In turn, the field distribution near focus can be controlled by shaping the excitation field wavefront, amplitude and polarization at the pupil of the objective using an active element (deformable mirror, spatial light modulator, acousto-optic lens).

We explore several directions:

• Adaptive optics: during in-depth imaging, the wavefront is distorted by the optical inhomogeneities within the sample, thereby reducing the signal level and the resolution of the images. Wavefront correction can be used to restore image quality in aberrating samples.

• Bessel beams are an efficient strategy for rapidly probing the nonlinear properties of extended volumes.

• More generally, focus engineering modifies phase-matching and image contrast in coherent nonlinear microscopy (e.g. THG, SHG, CARS).

Related publications

Efficient second-harmonic imaging of collagen in histological slides using Bessel beam excitation
N. Vuillemin, P. Mahou, D. Débarre, T. Gacoin, P.-L. Tharaux, M.-C. Schanne-Klein, W.Supatto, E. Beaurepaire
Scientific Reports 6, 29863 (2016).
3D resolved mapping of optical aberrations in thick samples
J. Zeng, P. Mahou, M.-C. Schanne-Klein, E. Beaurepaire, D. Débarre
Biomed. Opt. Express 3(8), 1898-1913 (2012).
Third-harmonic generation microscopy with Bessel beams: a numerical study
N. Olivier, D. Débarre, P. Mahou, E. Beaurepaire
Opt. Express 20(22), 24886-24902 (2012).
Accuracy of correction in modal sensorless adaptive optics
A. Facomprez, E. Beaurepaire, D. Débarre
Opt. Express 20(3), 2837-2849 (2012).
Simple characterisation of a deformable mirror inside a high numerical aperture microscope using phase diversity
D. Débarre, T. Vieille, E. Beaurepaire
J. Microsc. 244 (2), 136-143 (2011).
Dynamic aberration correction for multiharmonic microscopy
N. Olivier, D. Débarre, E. Beaurepaire
Opt. Lett. 34(20), 3145-7 (2009). PDF.
Two-photon microscopy with simultaneous standard and extended depth of field using an acoustic gradient-index lens
N. Olivier, A. Mermillod-Blondin, C.B. Arnold, E. Beaurepaire
Opt. Lett. 34(11), 1684-6 (2009). PDF.
Third-harmonic generation microscopy with focus-engineered beams: a numerical study
N. Olivier, E. Beaurepaire
Opt. Express 16(19), 14703-14715 (2008).