Speckle, a granular structure appearing in images and diffraction patterns produced by objects that are rough on the scale of an optical wavelength, is a ubiquitous phenomenon, appearing in optics, acoustics, microwaves, and other fields. This book provides comprehensive coverage of this subject, including both the underlying statistical theory and the applications of this phenomenon. This second edition offers improvements of several topics and addition of significant amounts of new material, including discussion of: generalized random walks, speckle in the eye, polarization speckle (and the statistics of the Stokes parameters in a speckle pattern), the effects of angle and wavelength changes on speckle, the statistics of speckle from “smooth” surfaces, and a spectrometer based on speckle. Many new references are also included. As with the first edition, a multitude of areas of application are covered.
“In the mid-1960s, a young Joseph Goodman, working at the Stanford Electronics Laboratories, wrote a detailed, but unpublished, report that established the basic statistical properties of speckle. Forty years later he wrote the most comprehensive book on the subject—Speckle Phenomena in Optics: Theory and Applications (2007), which became an instant classic and is the definitive text book. Goodman, the master of his subject, now presents an excellent second edition of an already excellent book.”
—Christopher Dainty, National University of Ireland, Galway, Ireland
“This second edition of Goodman’s classic Speckle Phenomena in Optics tells it all. It gives a detailed description of speckle, explains the techniques for suppressing speckle, and gives several applications of speckle in imaging and metrology.”
—James C. Wyant, University of Arizona
“When Goodman’s Speckle Phenomena in Optics was published in 2007, it became my primary reference for understanding speckle, which occurs in many diverse areas such as coherent optics, radar, and ultrasound. This second edition maintains Goodman’s signature clarity.”
—James R. Fienup, University of Rochester
Forward and backward propagation can both be modeled in terms ofWigner distributions or alternatively in terms of spatial frequency transfer functions. We use both formalisms to show that, for non-evanescent waves, forward propagation in a negative index material is equivalent to backward propagation in a positive index medium. We consider the implications of this fact for several specific problems, including imaging 3D objects, imaging through thin phase screens, Fresnel holography, and speckle.
The contrast of a speckle pattern, defined as the ratio of the standard deviation of intensity to the mean intensity, is an
important parameter that can yield useful information in vibration analysis, and surface roughness measurement. It is
also of inherent interest in the measurement of scattering by coherent X-rays. Under some circumstances, the light levels
at which contrast measurements must be made are low, and the measurement of speckle fluctuations is complicated by
the presence of noise associated with discrete detected photoevents. In addition, the measurements are made over a finite
integration time and a finite integration area, so it is the contrast of the integrated intensity that is of interest. The goal of
this paper is to explore the effects of both photoevent noise and source fluctuations on the measurement of speckle contrast.
Thus in themost general case, there are three sources of randomness, source fluctuations, random scattering and photoevent
fluctuations. Partial motivation for the investigation is understanding the photoevent statistics and speckle count contrast
for synchrotron and fee-electron laser sources.
We explore certain symmetry properties of the Fourier spectrum of speckle from smooth objects and the effects of these symmetries on image speckle contrast. The cases examined include bright-field imaging, dark-field imaging, and single-sideband imaging.
Since it was first observed in the early 1960s, speckle has become important in many different applications. In this paper we biefly discuss its role in holography, coherence tomography, projection TV, fiber-optic communications, lithography, optical radar detection, and metrology.
In image acquisition, the captured image is often the result of the object being convolved with a blur. Deconvolution is necessary to undo the effects of the blur. However, in reality we often know very little of its exact structure, and therefore we have to perform blind deconvolution. Most existing methods are computationally intensive, Here, we show that if the blur is symmetric, we have an efficient algorithm for deconvolution based on polynomial factorization in the z-domain.
In image acquisition, the captured image is often the result of the object being convolved with a blur functional. Deconvolution is necessary in order to undo the effects of the blue. However, in real life we may have very little knowledge of the blur, and therefore we have to perform blind deconvolution. One major challenge of existing iterative algorithms for blind deconvolution is the enforcement of the convolution constraint. In this paper we describe a method whereby this constraint can be much more easily implemented in the frequency domain. This is possible because of Parseval's theorem, which allows us to relate projection in the space and frequency domains. Our algorithm also incorporates regularization of the estimated image through the use of Wiener filters. The restored images are compared to the original and noisy blurred images, and we find that the restoration process indeed provides an enhancement in visual quality.
In this paper, we introduce a novel self-routed wavelength-addressable switching network (SWANET) that provides wavelength-transparent optical data paths between end-point, configured by wavelength-coded optical signals. The network is based on a new scheme for encoding destination addresses using a sequence of wavelengths. This allows large networks to be constructed using a moderate number of available wavelengths. The multistage switch architecture may be used either as a circuit switch or as a packet switch. We describe the architecture of SWANET and the design of its switch nodes. We also analyze the effect of fiber dispersion on the transmission time of the header and evaluate the tradeoffs involved in minimizing the header transmission time.
We have designed, built, and tested a sixteen channel fiber optic switching system based on the use of a bulk acousto-optic (AO) Bragg cell. The operational configuration known as a 'barrel shift' was developed specifically for fiber optic data acquisition system upgrades for the Collider Detector at Fermilab (CDF) in Batavia, Illinois. The prototype switch was delivered to CDF and is planned for tests targeting CDF upgrades in the next few years. Its use is intended for switching systems that specifically route time division multiplexed data channels. The acousto-optic barrel shifter (AOBS) simultaneously switches 16 parallel input optical fibers through a sequence of 16 separate states; after a complete cycle, all input channels have been routed to all output fibers for a total of 256 separate connections. The performance of the switch was demonstrated by switching transition times of 1 microsecond(s) ec, bit-error-rates (BERs) less than 10-12 at 1.2 Gbits/sec, operation over a range of optical wavelengths from 1285 nm to 1320 nm, and low dependence on optical polarization. The optics package was contained in a portable enclosure 12 inches wide, 6 inches in height, and 16 inches in length.
A method for designing and recording a holographic achromat, composed of two holographic optical elements (HOEs), is presented. The method is demonstrated with a doublet recorded at 488 nm for application at a central frequency of 820 nm. A near-diffraction-limited focus and high diffraction efficiency are achieved over a comparatively wide spectral range.
Since optical communication is preferable for establishing connections exceeding a certain critical length, for large system sizes the beneficial use of normally conducting wires for the shortest connections becomes an edge effect and can be ignored. This suggests that the performance and cost of an all optical computer might not be much inferior to an optimal hybrid alternative. We argue that for applications for which high bit repetition rates are useful despite large propagation delays, it might make sense to contemplate the construction of an optical digital computer.
As a parallelism of digital computers increases, the limitations associated with interconnecting a large number of processors becomes a greater and greater constraint on system performance. For example, as we pack more and more processors of a given size together in a single machine, naturally the physical dimensions of the machine must grow, and with that growth comes an increase in the maximum time delay experienced in communicating between the most distant processors in the array. To a degree that depends on the algorithm being executed and its communication requirements, that communication latency between different parts of the machine ultimately poses a limit to the speed with which the machine can solve problems. Our purpose in this paper is to discuss some of the fundamental aspects of the problem described above. We consider in what follows two different cases: (1) all interconnections are optical, and (2) all interconnections are electrical. Of course with a hybrid set of interconnects (i.e. part optical and part electrical), better performance can be achieved. However, we do not consider hybrid strategies in this paper.
We demonstrate the application of optical amplifiers and polymer-dispersed liquid-crystal (PDLC) shutters to electrically reconfigurable fiber optic delay line signal processors. Two 8-tap finite impulse response (FIR) fiber filter modules were fabricated. These two modules can also be interconnected in a cascaded or parallel configuration to implement a 16-tap fiber FIR filter. An erbium-doped fiber amplifier with a peak gain of about 20 dB was used to compensate for the large optical losses involved in the filters due to the large tap numbers. The relatively inexpensive PDLCs were used to realize electrically reconfigurable analog tap weights. The individual fiber filters were then evaluated for their impulse and frequency responses. The fabricated filters used single-mode fibers and fiber components and were polarization independent to within 0.5 dB. The sampling frequency was about 200 MHz, which can easily be upgraded into the gigahertz range. The tapping extinction ratio was about 13 dB with subkilohertz tunability speed. The amplified spontaneous emission noise can limit the filtering performance unless appropriate spectral filtering is included before detection. These optically amplified electrically reconfigurable fiber signal processors have the potential to lead to the realization of complex programmable and adaptive optical systems.
A new approach to the problem of handwritten signature verification is presented. This method exploits the regularity of length and curvature of a signature. Overall signature content at various angles is evaluated to form a slope histogram. Histograms are then passed to a classifier constructed from 10 valid signatures. Performance of the classifier on a data pool of 1000 valid and casually forged signatures is evaluated. In particular the equal error rate of this approach is shown to average 7 across 9 different subjects. Increases in the classifier error rates are noted when the forger is allowed some a priori knowledge of the target signature.
Purely diffractive doublets are corrected on-axis at two wavelengths. The doublets are then optimized with respect to their design parameters to achieve wideband imaging on-axis. Completed extensions to this design are also described. 2.
Computer simulations are used to investigate the effects of vlsi fabrication errors on the efficiency
of kinoforms. Fabrication and error models are described. Simulation results are presented and