Browsing by Author "Özaktaş, Haldun M."
Now showing items 120 of 149

About the Wigner distribution of a graded index medium and the fractional fourier transform operation
Özaktaş, Haldun M.; Mendlovic, D.; Lohmann, A. W. (SPIE, 199308)Upon propagation through quadratic graded index media, the Wigner distribution of the wavefunction of light rotates uniformly. As a consequence, a definition of fractional Fourier transforms based on rotating the functions ... 
Accumulated Gouy phase shift in Gaussian beam propagation through firstorder optical systems
Erden, M. F.; Özaktaş, Haldun M. (Optical Society of America, 199709)We define the accumulated Gouy phase shift as the onaxis phase accumulated by a Gaussian beam in passing through an optical system, in excess of the phase accumulated by a plane wave. We give an expression for the accumulated ... 
Analysis of the complex light field generated by a deflectable mirror array device
Ulusoy, Erdem; Onural, Levent; Özaktaş, Haldun M. (SPIE, 2006)An exact analysis of the scalar coherent monochromatic light field produced by a deflectable mirror array device is presented. The threedimensional light field is related to the tilt angles of the mirrors. The first ... 
Anamorphic fractional Fourier transform: optical implementation and applications
Mendlovic, D.; Bitran, Y.; Dorsch, R. G.; Ferreira, C.; Garcia, J.; Özaktaş, Haldun M. (Optical Society of America, 19951110)An additional degree of freedom is introduced to fractionalFouriertransform systems by use of anamorphic optics. A different fractional Fourier order along the orthogonal principal directions is performed. A laboratory ... 
Applications of the fractional Fourier transform in optics and signal processinga review
Özaktaş, Haldun M.; Mendlovic, D. (SPIE, 1996)The fractional Fourier transform The fractional Fourier transform is a generalization of the common Fourier transform with an order parameter a. Mathematically, the ath order fractional Fourier transform is the ath power ... 
Applications of the fractional Fourier transform to optical pattern recognition
Mendlovic, D.; Zalevsky, Z.; Özaktaş, Haldun M. (Cambridge University Press, 1998) 
A aurvey of signal processing problems and tools in holographic threedimensional television
Onural, L.; Gotchev, A.; Özaktaş, Haldun M.; Stoykova, E. (Institute of Electrical and Electronics Engineers, 2007)Diffraction and holography are fertile areas for application of signal theory and processing. Recent work on 3DTV displays has posed particularly challenging signal processing problems. Various procedures to compute ... 
Bessel functionsbased reconstruction of nonuniformly sampled diffraction fields
Uzunov, V.; Esmer, G. Bora; Gotchev, A.; Onural, Levent; Özaktaş, Haldun M. (IEEE, 2007)A discrete computational model for the diffraction process is essential in forward problems related to holographic TV. The model must be as general as possible, since the shape of the displayed objects does not bear any ... 
Beyond Nyquist sampling: a costbased approach
Özçelikkale, A.; Özaktaş, Haldun M. (Optical Society of America, 2013)A samplingbased framework for finding the optimal representation of a finite energy optical field using a finite number of bits is presented. For a given bit budget, we determine the optimum number and spacing of the ... 
Chirp filtering in the fractional Fourier domain
Dorsch, R. G.; Lohmann, A. W.; Bitran, Y.; Mendlovic, D.; Özaktaş, Haldun M. (Optical Society of America, 19941110)In the Wigner domain of a onedimensional function, a certain chirp term represents a rotated line delta function. On the other hand, a fractional Fourier transform (FRT) can be associated with a rotation of the ... 
Choice of sampling interval and extent for finiteenergy fields
Gulcu, T. C.; Özaktaş, Haldun M. (Institute of Electrical and Electronics Engineers Inc., 2017)We focus on the problem of representing a nonstationary finiteenergy random field, with finitely many samples. We do not require the field to be of finite extent or to be bandlimited. We propose an optimizable procedure ... 
Compact optical temporal processors
Mendlovic, D.; Melamed, O.; Özaktaş, Haldun M. (Optical Society of America, 1995)Optical signal processing can be done with timelens devices. A temporal processor based on chirpz transformers is suggested. This configuration is more compact than a conventional 4f temporal processor. On the basis of ... 
Comparison of fully threedimensional optical, normally conducting, and superconducting interconnections
Özaktaş, Haldun M.; Erden, M. F. (Optical Society of America, 19991210)Several approaches to threedimensional integration of conventional electronic circuits have been pursued recently. To determine whether the advantages of optical interconnections are negated by these advances, we compare ... 
Comparison of local and global computation and its implications for the role of optical interconnections in future nanoelectronic systems
Özaktaş, Haldun M.; Goodman J. W. (Elsevier, 1993)Various methods of simulating diffusion phenomena with parallel hardware are discussed. In particular methods are compared requiring local and global communication among the processors in terms of total computation time. ... 
Complex signal recovery from multiple fractional Fouriertransform intensities
Ertosun, M. G.; Atli, H.; Özaktaş, Haldun M.; Barshan, B. (Optical Society of America, 20050810)The problem of recovering a complex signal from the magnitudes of any number of its fractional Fourier transforms at any set of fractional orders is addressed. This problem corresponds to the problem of phase retrieval ... 
Complex signal recovery from two fractional Fourier transform intensities: order and noise dependence
Ertosun, M. G.; Atlı, H.; Özaktaş, Haldun M.; Barshan, B. (Elsevier, 200501)The problem of recovering a complex signal from the magnitudes of two of its fractional Fourier transforms is addressed. This corresponds to phase retrieval from the transverse intensity profiles of an optical field at two ... 
Computeraided analysis and simulation of complex passive integrated optical circuits of arbitrary rectilinear topology
Önal, G.; Altintaş, A.; Özaktaş, Haldun M. (SPIE, 199405)Optical interconnections can be beneficially employed at the chiptochip or backplane level of highperformance computing systems. One method of providing high speed and density interconnections among a large number of ... 
Condition number in recovery of signals from partial fractional fourier domain information
Oktem F. S.; Özaktaş, Haldun M. (Optical Society of America, 201306)The problem of estimating unknown signal samples from partial measurements in fractional Fourier domains arises in wave propagation. By using the condition number of the inverse problem as a measure of redundant information, ... 
Connectivity models for optoelectronic computing systems
Özaktaş, Haldun M. (Springer, Berlin, Heidelberg, 200005)Rent’s rule and related concepts of connectivity such as dimensionality, linelength distributions, and separators have found great use in fundamental studies of different interconnection media, including superconductors ... 
Continuous and discrete fractional fourier domain decomposition
Yetik, İ. Şamil; Kutay, M. A.; Özaktaş, H.; Özaktaş, Haldun M. (IEEE, 2000)We introduce the fractional Fourier domain decomposition for continuous and discrete signals and systems. A procedure called pruning, analogous to truncation of the singularvalue decomposition, underlies a number of ...