A prototype of a scalable and potentially low-cost stacked array piezoelectric deformable mirror (SA-PDM) with 35 active elements is presented in this paper. This prototype is characterized by a 2 μm maximum actuator stroke, a 1.4 μm mirror sag (measured for a 14 mm × 14 mm area of the unpowered SA-PDM), and a ±200 nm hysteresis error. The initial proof of concept experiments described here show that this mirror can be successfully used for shaping a high power laser beam in order to improve laser machining performance. Various beam shapes have been obtained with the SA-PDM and examples of laser machining with the shaped beams are presented.

The distinct optical absorption spectra of the two layers allowed spectroelectrochemical measurements to probe the electrochemical activity of the individual layers during the switching of the Prussian blue layer.We found that for producing layers of equal optical density, the thickness of the layers had to be different due to a difference in oscillator strength for the metal-to-metal charge-transfer transition. The films used here had a thickness of 300 AE 70 nm and 30 AE 15 nm for the FeCr and FeFe sub-layers, respectively.The colouration efficiency was found to be 147.8 AE 0.8 cm 2 C À1 for the multilayered film. These resultsshow that it is possible to obtain bilayers of Prussian blues that, with a unique optical spectral fingerprint of each sub-layer, retain the electrochromic functionality and therefore enable layer-sensitive studies of charge-transfer processes in thin film heterostructures of multifunctional materials.

AlN thin film ultrasonic transducers are being developed for non-destructive testing (NDT) applications in detection and monitoring in a high temperature environment. The ultrasonic transducers were fabricated by RF sputter deposition of c-axis oriented AlN films on aluminum alloy and carbon steel substrates. High temperature performance and durability of the transducers were investigated using pulse-echo experiments at elevated temperatures, and the transducer failure mode was characterized. Results showed that the sputtered AlN films maintained a stable crystalline structure and orientation at elevated temperatures up to 600 °C. The high temperature performance of the ultrasonic transducers, however, was limited by the deterioration of substrate properties. The high temperature limit for the films on aluminum alloy was found to be the melting temperature of the substrate. The AlN films deposited on the carbon steel substrate operated up to 500 °C, but if the temperature was increased further, rapid surface oxidation of the carbon steel caused the transducer to fail.

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The ability to reduce SQUID dimensions into the submicrometer or nanometer regime points the way towards novel applications, particularly in emerging fields such as quantum information processing, single-photon/particle detection, and experimental studies of nano-scale entities such as Bose-Einstein condensates. We report here on our ongoing work combining traditional thin-film and photolithographic fabrication processes with computer-aided-design software and focused ion beam milling to realize sub-micrometer superconducting structures. Their magnetic field sensitivity, noise behavior, spatial resolution, and prospects for magnetic spin detection are discussed.

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Abstract-As metrology extends toward the nanoscale, a number of potential applications and new challenges arise. By combining photolithography with focused ion beam and/or electron beam methods, superconducting quantum interference devices (SQUIDs) with loop dimensions down to 200 nm and superconducting bridge dimensions of the order 80 nm have been produced. These SQUIDs have a range of potential applications. As an illustration, we describe a method for characterizing the effective area and the magnetic penetration depth of a structured superconducting thin film in the extreme limit, where the superconducting penetration depth λ is much greater than the film thickness and is comparable with the lateral dimensions of the device.

A flexible and low profile ultrasonic transducer was fabricated for non-destructive testing (NDT) applications by DC sputtering of 3 μm thick, c-axis oriented, ZnO film on 50 μm aluminium foil. Due to the thin foil-based construction, the transducer can be applied to curved objects and used in sites of restricted accessibility. The device has been used to demonstrate detection of simulated defects in a 45 mm diameter steel pipe, and for thickness measurement on a 3.1 mm thick flat carbon steel plate. Centre frequency measured on the flat plate was 24-29 MHz, with -6 dB bandwidth 4-7 MHz. The pulse duration depended on the couplant, at best 3 cycles or 0.12 μs using SONO Ultragel or epoxy couplant. Transducer performance was found to be comparable to a commercial 10 MHz piezoelectric ultrasonic transducer.