Phase microscopy of technical and biological samples through random phase modulation with a diffuserPercival F Almoro
DTU Fotonik, Department of Photonics Engineering, Danmarks Tekniske Universitet, Roskilde 4000, Denmark
Opt Lett 35:1028-30. 2010
..The technique offers a whole-field and high-resolution wavefront reconstruction of unstained microstructures. Phase maps of photoresist targets and human cheek cells are obtained to demonstrate the effectiveness of our method...
Single-plane multiple speckle pattern phase retrieval using a deformable mirrorPercival F Almoro
National Institute of Physics, University of the Philippines, Quezon City 1101, Philippines
Opt Express 18:19304-13. 2010
..A DM with a surface height of 25 microns and an aperture diameter of 5.2 mm may be used to reconstruct spherical phase patterns with 50-micron fringe spacing...
Angular displacement and deformation analyses using a speckle-based wavefront sensorPercival F Almoro
DTU Fotonik, Department of Photonics Engineering, Danish Technical University, Roskilde 4000, Denmark
Appl Opt 48:932-40. 2009
..The technique offers simple, high resolution, noncontact, and whole field evaluation of three-dimensional objects before and after undergoing rotation or deformation...
Wavefront sensing using speckles with fringe compensationPercival F Almoro
DTU Fotonik, Department of Photonics Engineering, DK 4000 Roskilde, Denmark
Opt Express 16:7608-18. 2008
..The numerical phase-error correction system described in this study can be extended to other types of phase errors such as those due to aberrations if optical elements are present in the setup or due to perturbations in the environment...
Enhanced deterministic phase retrieval using a partially developed speckle fieldPercival F Almoro
National Institute of Physics, University of the Philippines, Quezon City 1101, Philippines
Opt Lett 37:2088-90. 2012
..The SLM setup enables a fast and accurate recording of speckle intensity. Experimental results are in good agreement with those obtained using the iterative phase retrieval and digital holographic methods of wavefront reconstruction...
Numerical correction of aberrations via phase retrieval with speckle illuminationPercival F Almoro
Department of Photonics Engineering, Danish Technical University, Roskilde 4000, Denmark
Opt Lett 34:521-3. 2009
..Numerical correction of the perturbed wavefront is performed based on rms error and the Strehl ratio. Restoration of the wavefront from a phase object with high spatial frequency content shows the effectiveness of our method...
Quantization analysis of speckle intensity measurements for phase retrievalAnne Margarette S Maallo
National Institute of Physics, University of the Philippines, Diliman, Quezon City 1101, Philippines
Appl Opt 49:5087-94. 2010
..Computer memory requirements may be eased down by 2.4 times if a 4 bit instead of an 8 bit camera is used. This may facilitate rapid speckle data acquisition for dynamic wavefront sensing...
Numerical correction of optical vortex using a wrapped phase map analysis algorithmAnne Margarette S Maallo
National Institute of Physics, University of the Philippines, Diliman, Quezon City 1101, Philippines
Opt Lett 36:1251-3. 2011
..The developed algorithm can be applied to absolute phase and phase difference maps obtained through any reconstruction method...