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The fabrication of lightweight and optically transparent arrays of microplasma devices having microcavities fabricated by a polymer-based replica molding process is reported. This process enables arrays of microcavity plasma devices and connecting channels with feature sizes as small as 20 μm to be produced inexpensively and precisely over surface areas of at least tens of square centimeters. Devices having transparent electrodes and substrates (including glass and flexible plastic) have been operated successfully at rare gas pressures up to 700 torr. Individual microplasma pixels with cross-sectional dimensions of 200 × 200 μm2 and 50 × 50 μm2, as well as plasma channels having widths of 20 and 150 μm and aspect ratios (channel length : width) as large as 104 : 1, have been fabricated and tested. Representative voltage-current data for these structures and lifetime measurements for a 20 × 20 pixel array are presented. [ABSTRACT FROM AUTHOR]

This letter describes the fabrication and performance of microplasma devices and arrays by a replica molding process in which the substrate is a flexible and ultraviolet (UV) transparent glass/polymer hybrid structure. In particular, ultrathin flexible glass sheets were embedded into the device so as to minimize outgassing of undesirable gas species and reinforce flexible substrates from the fatigue. Extended lifetime of the polymeric devices has been observed up to 200 h, with full recovery after refilling with gas. The major component of the devices has a high UV transmittance, and is transparent up to about 220 nm. [ABSTRACT FROM AUTHOR]

Thin films of Ge-Si alloys were deposited by 193 nm photolysis of GeH[sub 4]/Si[sub 2]H[sub 6], gas mixtures using an ArF laser. For substrate temperatures below 350 °C, deposition occurred only with the laser present, while for temperatures above 400 °C, film growth was little influenced by laser photolysis and resembled conventional chemical vapor deposition (CVD). The Si/Ge ratio in the films was about three times the P[sub Si[sub 2]H[sub 6]]/P[sub GeH[sub 4]], ratio of reactant partia1 pressures for deposition in either the laser photolysis or the CVD regime. This result indicates that there is strong cross chemistry between silicon and germanium-bearing species in the gas phase. Film stoichiometry was measured by Auger analysis and Raman spectroscopy, with both methods leading to the same film composition. [ABSTRACT FROM AUTHOR]

Microplasma arrays and channels fabricated on plastic substrates by replica molding are well suited for biomolecule detection in liquid flow streams. Arrays of orthogonally oriented linear channels with cross-sectional areas of 100 × 100 µm² have been operated in Ar/3% N2 gas mixtures at atmospheric pressure. Similar experiments with arrays of parallel linear channels having cross-sectional areas of 200 × 100 µm² and lengths of 6 cm have also been conducted. Spatially uniform emission in the near ultraviolet (λ ~300-400 nm) from the microcavity plasma sources and the photoluminescence of organic molecules in solution in adjoining channels have been observed. [ABSTRACT FROM AUTHOR]

Microchemical reactors consisting of parallel linear arrays of interconnected cylindrical microcavity plasma devices have been fabricated by replica molding in ultraviolet-curable polymer. Tests of 10 × 10 arrays of 400-µm-diameter devices with 125-µm-wide gas flow channels have been conducted in rare gas and Ar/CS2 flows and excitation of the array with a sinusoidal voltage. Visible chemiluminescence (λ ~ 505 nm) resulting from the A → X transition of CS2+ and the deposition of a (C-S)n microstructured polymer have been observed in the Ar/CS2 flow experiments. [ABSTRACT FROM AUTHOR]

Atomic and molecular emissions provide a convenient diagnostic of the spatial uniformity of the electrical characteristics of Si microcavity discharge arrays. 10 × 10 arrays of (50 μm)², inverted pyramidal Si microcavity pixels have been studied with Ne, Ar, and Ar/N2 gas mixtures at pressures up to 800 torr. Nonuniform power loading of pixels in the array, as well as the comparative strength of the electric field within each pixel at the device perimeter, are evident from images of the surface emission from the array. [ABSTRACT FROM AUTHOR]

Spatially uniform microdischarges in Xe at pressures of 300-800 torr have been produced in a 90-μm gap between 1.5-mm-diameter tungsten rods (plasma volume of ∼160 μL), and applied to the laser spectroscopy of the Xe2 excimer. Calculations and spectral simulations indicate that the gas temperature in the plasma reaches 900 K for a steady-state current density of 0.23 A-cm-2. Laser-induced, fluorescence suppression spectroscopy in the afterglow of the crow-barred discharge reveals well-developed vibrational bands in the 680-800-nm region tentatively attributed to 5(1g) ← a³Σu+ (1u Ou-transitions of Xe2. [ABSTRACT FROM AUTHOR]

Spatially uniform microdischarges in Xe at pressures of 300-800 torr have been produced in a 90-μm gap between 1.5-mm-diameter tungsten rods (plasma volume of ∼160 μL), and applied to the laser spectroscopy of the Xe2 excimer. Calculations and spectral simulations indicate that the gas temperature in the plasma reaches 900 K for a steady-state current density of 0.23 A-cm-2. Laser-induced, fluorescence suppression spectroscopy in the afterglow of the crow-barred discharge reveals well-developed vibrational bands in the 680-800-nm region tentatively attributed to 5(1g) ← a³Σu+ (1u Ou-transitions of Xe2. [ABSTRACT FROM AUTHOR]

Editorial. Expresses the editor's appreciation to all those people who support the Institute of Electrical and Electronics Engineer (IEEE) Journal of Quantum Electronics. Reviewers and Associate Editors.

Editorial. Announces the appointment of Leon Esterowitz as editor of 'IEEE Journal of Quantum Electronics.' Esterowitz's capabilities to become editor.

Two color optical pumping, both above (anti-Stokes pump or ASP) and below (Stokes pump) the lasing wavelength, was adopted to reduce the net quantum defect (QD) in a solid-state Yb-doped fiber laser. The reduction in QD was achieved by converting a substantial portion of the gain medium's phonons directly into useful photons through a dual-wavelength excitation (DWE) mechanism. Since this is achieved through the usual processes of absorption and stimulated emission associated with lasing, high efficiency can be maintained. Both time domain and power measurements are presented, demonstrating a 13.2% reduction of the system's net QD and a 13.8% reduction in the lasing threshold power. These values were limited only by the available ASP power. Laser slope efficiency, with respect to launched ASP power, was found to be as high as 38.3%. A finite difference time domain model, developed to elucidate the role of both pumps in populating the upper states, corroborated the experimental findings. The DWE concept proposed here opens the door to an "excitation-balanced" type of self-cooled fiber laser. Simulation results also suggest that the technique is scalable and conceptually applicable to other solid-state laser systems. [ABSTRACT FROM AUTHOR]

Mercury trapped ion clocks have demonstrated great long-term frequency stability and robustness. In this paper, we report a demonstration of an integrated 100-cc physics package in an effort to develop a micromercury trapped ion clock with high frequency stability. The physics package consists of a sealed 30-cc vacuum tube with one layer of magnetic shielding, light source, and detector assembly. A field emitter array and a 194-nm microplasma lamp were employed together with a microtrap tube to reduce the size and power consumption for a mercury trapped ion clock. We show that the 100-cc physics package is capable of providing a fractional frequency stability of 1 × 10 − 11 τ − 1 / 2 down to 5 × 10 − 14 after a few hours of integration. We also show a set of environmental sensitivity evaluations as well as the clock frequency retrace. [ABSTRACT FROM AUTHOR]

The article presents monolithic strong magnetic induction at the mtesla to tesla level provides essential functionalities to physical, chemical, and medical systems. Topic include semiconductor processing or 2.5D microelectromechanical systems (MEMS) technology, which is naturally contrary to the optimum design principle of 3D magnetic induction system on the macro scale.

Self-organization of periodic, streamer-like ionization waves in planar microplasma devices having a dielectric barrier discharge structure is observed. In contrast to plasma propagation in arrays of microchannels or microcavities, the ionization waves originate from a single point but rapidly sub-divide into as many as 10 'branch' plasma wave packets that eventually recombine. In less than 70 ns, the self-organization of the spatially-periodic array of co-propagating branches is complete and two successive sets of waves, separated in distance and time by ∼1.8 mm and ∼50 ns, respectively, are generated. The mean propagation velocity of each plasma packet is greater than 70 km s−1 but values as large as 150 km s−1 have been measured. Because the propagation path for all subsequent streamers is established by the first set of plasma packets, the intensity of the second set is noticeably enhanced. The average length of the primary branches is ∼1.5 mm but reaches a maximum of ∼4.5 mm as the wave packets travel an overall distance of 1 cm. These phenomena are interpreted in terms of photoelectron emission from the floor and walls of the shallow dielectric microcavity, induced by radiation from the advancing packets, and the rapid collapse of the sheath of each microplasma owing to the accumulation of charge on the underlying dielectric. The spatial profiles of the propagating plasmas suggest that generating and probing plasma solitons may now be feasible. [ABSTRACT FROM AUTHOR]

Low-temperature nonequilibrium plasma has been produced within the microcavities of a single sheet of aluminum wire fabric. The fabric is composed of two sets of interwoven, orthogonally oriented Al wires and each of the sets serves as an electrode for the array of dielectric barrier devices. Carefully controlled anodization of the fabric electrically and chemically isolates the two sets of wires from each other with a thin barrier of nanoporous aluminum oxide. The resulting material is flexible, and cylindrical microcavity plasma lamps operating in Ne have been demonstrated. [ABSTRACT FROM AUTHOR]

Presents an obituary for laser physicist Howard Thomas Powell who died on November 15, 2000.