Wavefront compensation for deep tissue optical microscopy Full - PowerPoint PPT Presentation

Wavefront compensation for deep tissue optical microscopy Full correction System correction 60 mW 300 mW vs. 5 μ m 5 μ m Depth = 800 micron Meng Cui Tang et.al. Proceedings of the National Academy of Sciences 109, 8434 ‐ 8439 (2012). HHMI Janelia Farm Research Campus

Limitations of optical microscopy Biological tissues are rarely transparent http://beautifulafricanwildanimalspets.blogspot.com/2012/02/jellyfish.html Why optics? Why not sound, x ‐ ray? Molecular contrast, resolution, and sensitivity

Aberration and scattering http://en.wikipedia.org/wiki/Mirage http://www.soundbuzz360.com/cloud/ Same physical effect: Wavefront distortion caused by inhomogeneous refractive index

The principle of Optical phase conjugation (OPC) works for both aberration and scattering Direct focusing without What if there is a OPC wavefront control guide star?

Multidither coherent optical adaptive techniques (COAT) W. B. Bridges, et al. Applied Optics, Vol. 13, Issue 2, pp. 291 ‐ 300 (1974)

Focusing light through highly scattering medium onto a detector target Meng Cui, Optics Letters, Vol. 36 Issue 6, pp.870 ‐ 872 (2011)

Experiment results Sample: glass diffuser Wavelength: 785 nm Focusing objective: NA 0.5, 20x Observation objective: NA 0.9, 60x Observed transmission Observed transmission with Measured wavefront profile without wavefront correction wavefront correction Meng Cui, Optics Letters, Vol. 36 Issue 6, pp.870 ‐ 872 (2011)

Experiment in action

Two ‐ photon scope Tang et.al. Proceedings of the National Academy of Sciences 109, 8434 ‐ 8439 (2012).

Test 1, imaging beads through mouse skull System correction IMPACT measured phase Full correction Fluorescence signal [a.u.] Fluorescence signal [a.u.] 1500 15000 Phase [rad] 1000 10000 5000 500 5  m 0 0 Tang et.al. Proceedings of the National Academy of Sciences 109, 8434 ‐ 8439 (2012).

Limited field of view  anisoplanatism Wavefront correction plane Wavefront correction plane

Solution for imaging through intact skull anisoplanatism  isoplanatism Wavefront correction plane Image relay

Test 2, power dependence Tang et.al. Proceedings of the National Academy of Sciences 109, 8434 ‐ 8439 (2012).

Test 3, imaging T cell inside lymph nodes Full correction System correction 60 mW 300 mW vs. 5 μ m 5 μ m Depth = 800 micron Tang et.al. Proceedings of the National Academy of Sciences 109, 8434 ‐ 8439 (2012).

Test 4, stability in live animal Tang et.al. Proceedings of the National Academy of Sciences 109, 8434 ‐ 8439 (2012).

Summary  Purely based on signal intensity measurement  High speed  Aberration + scattering  Simple modification to TP scope

High speed + large number of degrees of freedom AO Meng Cui, Optics Express, Vol. 19, Issue 4, pp. 2989 ‐ 2995 (2011)

k space modulation based wavefront measurement and correction system Meng Cui, Optics Express, Vol. 19, Issue 4, pp. 2989 ‐ 2995 (2011)

Test with glass diffuser Current speed: 1 ms /degree of freedom Total DAQ time: 400 ms Next generation 1 ‐ 10  s /mode Meng Cui, Optics Express, Vol. 19, Issue 4, pp. 2989 ‐ 2995 (2011) After wavefront correction Measured wavefront Before wavefront correction

Acknowledgement Na Ji, Karel Svoboda, Eric Betzig, Charles Shank, Mats Gustafsson, Philipp Keller, Jianyong Tang, Vijay Iyer, Jinyang Liu, Amy Hu, Kerry Sobieski, Lakshmi Ramasamy, Lin Shao, Raju Tomer, Liang Gao, Thomas Planchon http://www.janelia.org/campus ‐ community/janelia ‐ farm ‐ campus http://www.janelia.org/campus ‐ community Open Positions: Postdoc Research Scientist