Laser beam focusing through the scattering medium using bimorph deformable mirror and spatial light modulator

Bimorph deformable mirror with the clear aperture of 50 mm and 48 control electrodes and spatial light modulator with resolution of 1920x1080 pixels were used to increase the efficiency of focusing of partially coherent laser radiation, propagated through the 5 mm layer of the scattering suspension of 1 um polystyrene microspheres, diluted in distilled water, with the concentration values ranging from 105 to 106 mm-3. Medium with such parameters can be considered as an equivalent to the mid-dense fog layer with the length ranging from 300–500 meters up to 5 kilometers. Shack- Hartmann sensor was used to measure the distortions of averaged wavefront of laser beam, and CCD camera was used to estimate the intensity distribution of the focal spot in the far-field. Numerical and experimental investigation of the focusing improvement showed that it is possible to increase the peak intensity of the focal spot up to 45–60 %.

[2]  A. Kudryashov,et al.  Bimorph deformable mirror with a high density of electrodes to correct for atmospheric distortions. , 2019, Applied optics.

[3]  J. Wyant,et al.  Basic Wavefront Aberration Theory for Optical Metrology , 1992 .

[4]  W. Southwell.  Wave-front estimation from wave-front slope measurements , 1980 .

[5]  William J. Brown,et al.  Deep tissue imaging using spectroscopic analysis of multiply scattered light , 2014 .

[6]  Yongkeun Park,et al.  Digital optical phase conjugation for delivering two-dimensional images through turbid media , 2013, Scientific Reports.

[7]  Dan Zhu,et al.  Visible and near-infrared spectroscopy for distinguishing malignant tumor tissue from benign tumor and normal breast tissues in vitro , 2013, Journal of biomedical optics.

[8]  H. Kogelnik,et al.  Holographic Imaging Through a Random Medium , 1968 .

[9]  Julia Sheldakova,et al.  A device based on the Shack-Hartmann wave front sensor for testing wide aperture optics , 2016, SPIE OPTO.

[10]  V. E. Zavalova,et al.  Shack — Hartmann wavefront sensor for measuring the parameters of high-power pulsed solid-state lasers , 2010 .

[11]  Vadim Samarkin,et al.  Adaptive optics system for real-time wavefront correction , 2015 .

[12]  Wavefront analysis of the laser beam propagating through a turbid medium , 2015 .

[13]  Valentina Ye. Zavalova,et al.  Adaptive optical system based on bimorph mirror and Shack-Hartmann wavefront sensor , 2002, Optics + Photonics.

[14]  R. Shack,et al.  History and principles of Shack-Hartmann wavefront sensing. , 2001, Journal of refractive surgery.

[15]  Risto Myllylä,et al.  Visualisation of structural inhomogeneities in strongly scattering media using the method of spatially-resolved reflectometry: Monte Carlo simulation , 2011 .

[16]  S. Popoff,et al.  Measuring the transmission matrix in optics: an approach to the study and control of light propagation in disordered media. , 2009, Physical review letters.

[17]  A. Kudryashov,et al.  Formation of doughnut and super-Gaussian intensity distributions of laser radiation in the far field using a bimorph mirror , 2018 .

[18]  A. Priezzhev,et al.  Monte Carlo simulation of laser beam propagation in a plane layer of the erythrocyte suspension: comparison of contributions from different scattering orders to the angular distribution of light intensity , 2002 .

[19]  A. Kudryashov,et al.  Generation of custom modes in a Nd:YAG laser with a semipassive bimorph adaptive mirror , 2006 .

[20]  R G Lane,et al.  Wave-front reconstruction using a Shack-Hartmann sensor. , 1992, Applied Optics.

[21]  G. Lerosey,et al.  Controlling waves in space and time for imaging and focusing in complex media , 2012, Nature Photonics.

[22]  Alexis Kudryashov,et al.  Focusing laser beam through pinhole using bimorph deformable mirror , 2019, LASE.

[23]  J. Bertolotti,et al.  Non-invasive imaging through opaque scattering layers , 2012, Nature.

[24]  A. Mosk,et al.  Focusing coherent light through opaque strongly scattering media. , 2007, Optics letters.

[25]  L Wang,et al.  MCML--Monte Carlo modeling of light transport in multi-layered tissues. , 1995, Computer methods and programs in biomedicine.

[26]  Alexis Kudryashov,et al.  Adaptive optical elements for laser beam control , 2001, SPIE Optics + Photonics.

[27]  Alexis Kudryashov,et al.  Laser beam focusing through the dense multiple scattering suspension using bimorph mirror , 2019, BiOS.

[29]  A. L. Rukosuev,et al.  The use of M2 meter to correct for high-power laser aberrations , 2005, SPIE LASE.

[30]  Hema Ramachandran,et al.  IMAGING THROUGH TURBID MEDIA , 1999 .

[31]  Junzhong Liang,et al.  Objective measurement of wave aberrations of the human eye with the use of a Hartmann-Shack wave-front sensor. , 1994, Journal of the Optical Society of America. A, Optics, image science, and vision.

[32]  P. Michel,et al.  Generation of a single hot spot by use of a deformable mirror and study of its propagation in an underdense plasma , 2003 .

[33]  Demetri Psaltis,et al.  Imaging through turbid layers by scanning the phase conjugated second harmonic radiation from a nanoparticle. , 2010, Optics express.

[34]  D. Conkey,et al.  High-speed scattering medium characterization with application to focusing light through turbid media. , 2012, Optics express.

[35]  Joseph W. Goodman,et al.  WAVEFRONT‐RECONSTRUCTION IMAGING THROUGH RANDOM MEDIA , 1966 .

[36]  Alexis V. Kudryashov,et al.  Laser beam focusing through the scattering medium-low order aberration correction approach , 2018, Optical Engineering + Applications.

[37]  A. Mosk,et al.  Exploiting disorder for perfect focusing , 2009, 0910.0873.

[38]  Changhuei Yang,et al.  Focusing on moving targets through scattering samples. , 2014, Optica.

[39]  Jun Q. Lu,et al.  Determination of complex refractive index of polystyrene microspheres from 370 to 1610 nm , 2003, Physics in medicine and biology.

[40]  O. Katz,et al.  Looking around corners and through thin turbid layers in real time with scattered incoherent light , 2012, Nature Photonics.

[41]  I. Meglinski,et al.  Quantitative assessment of skin layers absorption and skin reflectance spectra simulation in the visible and near-infrared spectral regions. , 2002, Physiological measurement.