000105210 001__ 105210
000105210 005__ 20190509132128.0
000105210 0247_ $$2doi$$a10.5075/epfl-thesis-3873
000105210 02470 $$2urn$$aurn:nbn:ch:bel-epfl-thesis3873-8
000105210 02471 $$2nebis$$a5381216
000105210 037__ $$aTHESIS
000105210 041__ $$aeng
000105210 088__ $$a3873
000105210 245__ $$aAdaptive optics in speckle interferometry and in super-resolution
000105210 269__ $$a2007
000105210 260__ $$aLausanne$$bEPFL$$c2007
000105210 300__ $$a134
000105210 336__ $$aTheses
000105210 502__ $$aAndrea Poggialini, Daniele Inaudi, Erwin Hack
000105210 520__ $$aThis thesis describes innovative techniques for reducing speckle noise and improving the intensity profile of the speckle correlation fringes. The methods are based on reducing the range of the modulation intensity values of the speckle interference pattern. After the fringe pattern is corrected adaptively at each pixel, a simple morphological filtering of the fringes is sufficient to obtain smoothed fringes. The concepts are presented both analytically and by simulation by using computer-generated speckle patterns and experimental verifications are performed wherever possible. A new generalized method for designing continuous amplitude-only pupil filters for transverse superresolution using a nonlinear programming method is also presented. The thesis emphasises the principal advantage of amplitude-only filters over their phase-only counterparts, that the side lobe intensities can be highly reduced along with the spot size. A quantitative comparison with continuous phase-only filters as well as the two-zone binary phase filter is shown with respect to spot size and ratio of side lobe to central peak intensity. The work is extended to combine the advantages of amplitude and phase filters in one complex filter that performs better than either phase or amplitude filters designed so far. The performance here refers to having a smaller spot size along with higher peak to side lobe intensity ratio. Using numerical simulation the limitations of phase and amplitude filters are assessed. The experimental verification of the designed combination filter is performed with two LCD spatial light modulators used for displaying separately the phase and amplitude part of the filter. Results obtained from this setup confirm the simulation. Finally, the effect of optical superresolution on speckle correlations is studied. Simulations reveal that using a lateral super-resolution pupil filter more than twice the out of plane correlation length of the clear pupil can be achieved. This means that the measurement range in speckle correlation measurements doubles. To verify the correlation length an experiment is performed using a liquid crystal (LCD) spatial light modulator as a programmable superresolution filter. The results corroborate the simulation.
000105210 6531_ $$aDSPI
000105210 6531_ $$aCorrelation fringes
000105210 6531_ $$aAdaptive optics
000105210 6531_ $$aDeformation measurement
000105210 6531_ $$aLCD
000105210 6531_ $$aMorphological filtering
000105210 6531_ $$aPupil filter
000105210 6531_ $$aSuperresolution
000105210 6531_ $$aSuperspeckles
000105210 6531_ $$aDecorrelation
000105210 6531_ $$aDSPI
000105210 6531_ $$aFrange de corrélation
000105210 6531_ $$aOptique adaptative
000105210 6531_ $$aMesures de déformation
000105210 6531_ $$aLCD
000105210 6531_ $$aFiltre morphologique
000105210 6531_ $$aFiltre pupillaire
000105210 6531_ $$aSuperresolution
000105210 6531_ $$aSuperspeckles
000105210 6531_ $$aDécorrélation
000105210 700__ $$0(EPFLAUTH)163323$$aGundu, Phanindra Narayan$$g163323
000105210 720_2 $$0241647$$aRastogi, Pramod$$edir.$$g106189
000105210 8564_ $$s4296796$$uhttps://infoscience.epfl.ch/record/105210/files/EPFL_TH3873.pdf$$yTexte intégral / Full text$$zTexte intégral / Full text
000105210 909C0 $$0252031$$pIMAC$$xU10237
000105210 909CO $$ooai:infoscience.epfl.ch:105210$$pthesis-bn2018$$pDOI$$pENAC$$pthesis$$qDOI2$$qGLOBAL_SET
000105210 918__ $$aENAC$$bENAC-SGC$$cIS
000105210 919__ $$aIMAC
000105210 920__ $$a2007-10-11$$b2007
000105210 970__ $$a3873/THESES
000105210 973__ $$aEPFL$$sPUBLISHED
000105210 980__ $$aTHESIS