Controlling light Propagation in complex media for Imaging, focusing and Brillouin measurements

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dc.contributor.advisorScarcelli, Giulianoen_US
dc.contributor.authorEdrei, Eitan Yen_US
dc.contributor.departmentBioengineeringen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.date.accessioned2019-02-05T06:32:24Z
dc.date.available2019-02-05T06:32:24Z
dc.date.issued2018en_US
dc.description.abstractImaging and focusing light through turbid media are two fundamental challenges of optical sciences that have attracted significant attention in recent years. Traditional optical systems such as confocal microscopy, optical coherence tomography and multi-photon microscopy utilize ballistic photons traveling in straight trajectories to generate an image; however, with increasing depth, the signal to noise ratio (SNR) decreases as the number of ballistic photons decays exponentially. In the first part of this thesis I present two novel techniques for imaging through scattering medium by decoding seemingly random scattered light patterns and demonstrate the highest resolution and acquisition speed to date. For point scanning applications I also study methods to focus light through scattering materials and report on a fundamental trade-off between the focal point intensity and the focal plane in which it is generated. In the second part of the thesis I investigate how the ability to control light propagation within turbid media can be used to enhance point scanning measurements such as Brillouin scattering spectroscopy, a technology recently developed in our lab to characterize material stiffness without contact. To do this, I first present a novel optical system (“spectral coronagraph”) which yields an improved extinction ratio when inserted into Brillouin spectrometers to enable the spectral separation in the presence of scattering or close to interfaces. Additionally, to enhance the Brillouin signal, I apply adaptive optics techniques, first developed for astronomy applications, where the incident wave front is shaped to circumvent for optical phase aberrations. Using adaptive optics, I show signal enhancement in artificial and biological samples, an important feature in the context of Brillouin microscopy to promote high SNR imaging in practical scenarios.en_US
dc.identifierhttps://doi.org/10.13016/qctc-kpsx
dc.identifier.urihttp://hdl.handle.net/1903/21684
dc.language.isoenen_US
dc.subject.pqcontrolledOpticsen_US
dc.subject.pqcontrolledPhysicsen_US
dc.subject.pquncontrolledAdaptive opticsen_US
dc.subject.pquncontrolledBrillouin Spectroscopyen_US
dc.subject.pquncontrolledComputational imagingen_US
dc.subject.pquncontrolledCoronagraphen_US
dc.subject.pquncontrolledDeconvolutionen_US
dc.subject.pquncontrolledImaging through scatteringen_US
dc.titleControlling light Propagation in complex media for Imaging, focusing and Brillouin measurementsen_US
dc.typeDissertationen_US

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