A high precision, numerically controlled diamond turning machine has been developed for fabrication of asymmetric aspheric mirrors, such as toroidal mirrors used in soft x-ray optics. A workpiece is machined by a single-point diamond tool fly cutter. While the cutting spindle is rotating, cutting depth can be dynamically controlled according to programmed data synchronized with the current rotation angle of the spindle. The programmed data allow generation of a generalized figure. To achieve high figure accuracy, a straightness error compensation control is incorporated with the tool slide. The machine accepts a workpiece with maximum dimensions of 600 mm by 100 mm. A figure accuracy of 0.1 Am and surface roughness of 0.03 um Rmax have been achieved.

This editorial is devoted to the winners of various SPIE awards that were presented at the Society's 32nd Annual Symposium in San Diego this August and at the International Congress on Optical Science and Engineering in Hamburg this September.

Fiber Optic Communications, Second edition-Reviewed by r.C. Menendez; Lasers: invention to Application-Reviewed by Arthur H. Guenther

Rasterography was developed for measurements of three-dimensional surface height distribution. It is extended here to the measurement of strains due to changes in curvature under an object's deformation. The method is demonstrated for a cylindrical shell segment under static loading. However, the method is general in that it can be applied for any curved surface loaded statically.

Dynamic double-exposure holographic interferometry and sandwich holography were applied to the measurement of surface displacements resulting from the detonation of an explosive charge on the surface of rock models. A 10 J state-of-the-art ruby laser was used to illuminate three different rock models that were 0.75 m on a side and 0.4 m deep. In one model, a simulated tunnel was made by coring the rock specimen in a subsurface plane that was parallel to the face of the block. Another model involved the transmission and alteration of surface waves as they encountered a step change in the surface elevation. The remaining specimen consisted of an epoxy wedge overlying the rock base. As the wave system passed into the epoxy layer of this last specimen, new waves were generated that produced dramatically increased displacements and particle velocities on the surface of the epoxy layer. These interferometric patterns were so complex that it was necessary to utilize sandwich holography to determine the wave types and the signs of the displacements.

We present here a synthesis of our previous work in order to provide an overall model that describes the infrared image of ground terrain in terms of the heat balance of each image pixel. This approach relates the pixel radiance to two physical invariant properties and to the external heat input (output) source. Thus, the temporal variations of the statistical and spatial properties can be accounted for. Specifically, the model predicts a non-Gaussian distribution of the radiance over the scene, as well as the change of the probability density function with changing external heat source (the sun). The probability density function can be asymmetric. The radiance statistics are related to the image resolution. We show that the distribution approaches the normal distribution as the resolution decreases. The radiance spatial behavior can be described by an exponential correlation function. The present discussion shows that the correlation length describing a given type of terrain is time dependent. It is predicted that the correlation length decreases as the intensity of the heat source increases, i.e., that higher spatial frequencies are more pronounced at noon than at sunrise or sunset. The model can be used to predict the infrared image of a given scene. Most of the model predictions are supported by experimental results.

Highly stable selective absorptive coatings of copper oxides were deposited on commercially available galvanized iron substrates by a dip-and-dry technique. The optothermal, structural, and optical properties of these films were investigated. The deposition parameters for an optimum selective absorptive film were determined. A typical such coating gave solar absorptance (AM1) of 0.91 and thermal emittance (100°C) of 0.17. Up to 300°C, the film was adherent and stable, having a top layer of CuO and an under layer of CuO of varying composition (x =1 to 2). However, increasing the temperature beyond 400°C converted the film to CuO only.

Optical interconnection techniques have been suggested to reduce signal skew for clock distribution for silicon VLSI chips. One optical approach for clock distribution is to holographically map an optical signal from an off-chip source to several photoreceivers within small functional cells on a chip surface. Within each functional cell, the clock is distributed via short surface wires with negligible delays. In such a system, the primary source of timing uncertainty is due to fabrication-related variation of transistor parameters between identically drawn receivers on a chip. We present here an overview of the distribution system and two receiver designs. A test chip has been designed and fabricated, and laboratory measurements of transimpedance receiver parameters are presented. Analysis and simulation studies show that a phase-locked loop receiver based on a voltage-controlled ring oscillator can offer two orders of mag-nitude improvement in receiver skew over a simple transimpedance amplifier design, allowing a total synchronization uncertainty on the order of 55 ps while operating at 100 to 200 MHz and requiring much less layout area than the transimpedance amplifier.

An all-optical fiber-optic crossbar switch capable of interconnecting N input fibers to M output fibers with an arbitrary interconnect pattern has been constructed. The switch can use any 1-D or 2-D spatial light modulator capable of realizing N X M pixels and can be configured for permutations, full or partial broadcast, or "wired-oring" of several inputs to a given output. Values of N and M achievable depend on the light efficiency of the switch components and the data rate. A 4X4 switch has been built; in a computer switching environment, the approach is capable of realizing a 16 X16 switch at 1 Gb/s and a 32 X32 switch at >100 Mb/s. The development of the switch has included construction of both a PLZT switch array and a magneto-optic switch array. We report on the investigations of both technologies. Reconfiguration times in the range of a few microseconds to a few tens of microseconds are of interest. A reconfiguration time shorter than 20 ps was actually achieved.

This paper is concerned with surface enhanced second harmonic generation through delocalized electromagnetic resonances such as surface plasmons or guided waves at bare or coated metallic gratings. The formalisms presented are rigorous in the sense that the groove depth of the grating is not considered as a perturbative parameter. This allows us to show that there exists an optimum groove depth of the grating for which the enhancement of the second harmonic efficiency, as compared to the flat case, is the greatest. Shallow modulated gratings (10 -1) lead to optimum enhancement as high as 105. Emphasis is placed on the effect of the periodicity and of the profile of the grating on this optimum enhancement.

High power lasers tend to have significant spatial intensity structure across their pupils. Some high power applications, however, require nearly uniform intensity distributions at some plane of interest. Channel integrators offer a relatively simple and cost-effective means of making this conversion.

A plastic optical fiber tap has been developed. The plastic optical fiber is bent over a small radius, which causes core modes to be converted into cladding modes. These converted high order modes can then be removed from the fiber by attaching refractive-index-adjusted materials. In this paper, we propose a new type of optical fiber tap and investigate its transmission characteristics,- especially mode transformation in the multimode system.

New platinum-coated, vertically deflecting, grazing incidence mirrors with low surface roughness have been developed to prefocus bending magnet radiation from the Stanford Positron Electron Asymmetric Ring (SPEAR) storage ring into two Beam Line VIII grating mono-chromators. In our toroidal grating monochromator (TGM) branch there are two 12° deflecting prefocusing mirrors: a cooled chemically vapor deposited (CVD) SiC cylinder for one-to-one sagittal focusing followed by a fused-silica spheroid for tangential focusing with three-to-one demagnification. In our spherical grating branch the first mirror is a 5° vertically deflecting, cooled SiC toroid designed to focus tangentially on the monochromator entrance slits and sagittally on the exit slits. After the exit slits, a 4° deflecting fused silica mirror is used in each beam line to refocus onto the sample. For this application a cylinder of thin cross section is bent to approximate a toroid. The mirrors are now installed at the Stanford Synchrotron Radiation Laboratory, and performance measurements are planned. Qualitatively, the focus of the TGM optics at the entrance slits appears very good. In this paper we present mirror development highlights, including the choice of SiC for primary mirrors, the measured SiC surface roughness results, and the method developed to test the profile of the toroid during construction.

A new method is presented for destriping Landsat data and compen-sating for failed detectors. The basic spatial frequency composition of the degradation is determined from an easily computed one-dimensional power spectrum of the image. A convolutional restoration kernel is then created from a modified version of the power spectrum.

Utilizing heat conduction theory and thin film optics theory, we have derived an optical and thermal analytical model for phase change recording in a trilayer antireflection structure. The temperature field during recording with different latent heats of fusion and the incident beam distributions of a short pulse laser are calculated. The radial distributions of the temperature field at different times are described. The effect of latent heat on temperature-time behavior and the effect of the incident beam distribution on temperature-space behavior are discussed.

This paper presents a general formulation of multifaceted mirror configurations for transforming an arbitrary laser beam irradiance pattern into a uniform irradiance pattern. Three configurations are presented and compared. Two of these configurations are new: a strip integrator that reduces manufacturing complexity and an imaging integrator that minimizes deleterious diffraction effects. Aberration effects associated with the relaying or imaging of the irradiance pattern and a novel technique for correction are also discussed.