Iterative phase-amplitude retrieval with multiple intensity images at output plane of gyrator transforms

Abstract

For the iterative phase retrieval, multiple measured intensity images in output plane are only considered for accelerating the convergence. The amplitude and phase at the observed object plane of measurement system are unknown in this research. The observing system is composed of gyrator transform, in which several images are recorded by using several transform angles for the same input image. An amplitude-phase retrieval scheme is designed and tested. The numerical simulations have demonstrated that the amplitude and phase pattern within a very small error (less than 0.04 and 0.0005 for an 8-bit two-dimensional data) can be recovered after 1000 iterations.

Unitary Algorithm for Nonseparable Linear Canonical Transforms Applied to Iterative Phase Retrieval

“…It has been extended to allow other transforms take the place of the optical Fourier transform, such as the Fresnel transform [5] (including by means of a chirp placed in the Fourier plane [6]), fractional Fourier transform [5], [7], and the 1-dimensional linear canonical transform (1D-LCT) [8]. Phase retrieval based on intensities captured in planes related by one specific nonseparable transform, the gyrator transform, have also been reported [9], [10], [11], [12], [13], [14], [15]. The advantage of using these alternative systems is that increased flexibility for the system designer.…”

Reducing the variability in random-phase initialized Gerchberg-Saxton Algorithm

“…The decade of the 90's was specially productive due to the development of Personal Computers and Liquid Crystal Displays (LCDs) [2]. In the recent years, this application has become an increasing interest motivated, specially, by the display industry and 3D imaging systems, leading to an increment of the number of published works about this topic [3][4][5][6][7][8][9][10]. These fields, compared to planar optics, require an elevated number of pixels increasing notably the computation time.…”

Optical asymmetric image encryption using gyrator wavelet transform

“…Here, an input image is encrypted by two fractional orders and a series of scaling factors. Recently, optical gyrator transform system has been introduced for encrypting secret image [15,16]. However, due to inherent linearity such cryptosystems are not highly secure [17,18].…”