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A linear, segmented channel, microdischarge array having an ∼ 80 × 380 μm[SUP2] aperture and an active length of ∼1 cm, has been fabricated in a ceramic multilayer structure and characterized in Ne, Ar, and Xe. The length of this seven-section device is more than an order of magnitude larger than those for previous arrays (2-3 elements) of coaxial microdischarge devices, and the discharge segments are individually ballasted with integrated thick-film resistors. Pulsed and cw operation of the array for Xe pressures as large as 700 Torr has been demonstrated and experimental indications of gain on 0 the Xe[SUP+] 6p [SUP4]D[SUP0,SUB3/2]→6s [SUP4]P[SUB3/2] transition at 460.30 nm are presented. This device is well suited for the excitation of microlasers, either by electron impact pumping of gases and vapors, or by photoexcitation of solid state lasers in a slab geometry. [ABSTRACT FROM AUTHOR]

A three-stage, multilayer ceramic microdischarge device, having an active length of ∼267 μm and a cylindrical discharge channel 140-150 μm in diameter, has been developed and operated continuously in Ne gas. Stable glow discharges are produced for pressures above 1 atm, operating voltages as low as 137 V (at 800 Torr), and specific power loadings of ∼40 kW cm[sup -3]. The V-I characteristics for a fired ceramic structure exhibit a negative resistance, whereas the resistance is positive prior to firing. The manufacturability of the fabrication process as well as the "flow-through" and multistage design of this device make it well suited for the excitation of gas microlasers or the dissociation of toxic or environmentally hazardous gases and vapors. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Excitation spectra for the 4pπ [sup 3]Π[sub g]–a [sup 3]Σ[sub u][SUP ARRANGE="STAGGER"]+] system in [sup 20]Ne[sub 2] and [sup 22]Ne[sub 2] have been used to characterize the v=0 through v=3 levels in both electronic states. This is the first time levels with v>1 have been characterized experimentally in either dimer. Rotational analyses lead to B[sub e]- and α[sub e]-values of 0.5638 cm[sup -1] and -0.9000×10[sup -2] cm[sup -1] and of 0.5113 cm[sup -1] and -0.6651×10[sup -2] cm[sup -1] for the a [sup 3]Σ[sub u][SUP ARRANGE="STAGGER"]+] states in [sup 20]Ne[sub 2] and [sup 22]Ne[sub 2], respectively. The B[sub e]- and α[sub e]-values are, respectively, 0.5716 cm[sup -1] and -0.6429×10[sup -2] cm[sup -1] ([sup 20]Ne[sub 2]) and 0.5201 cm[sup -1] and -0.4172×10[sup -2] cm[sup -1] ([sup 22]Ne[sub 2]) for the 4pπ [sup 3]Π[sub g] state. The vibrational parameters ω[sub e], xω[sub e] are found to be 556.2, 10.2 cm[sup -1], and 593.2, 7.5 cm[sup -1] for the a [sup 3]Σ[sub u][SUP ARRANGE="STAGGER"]+] state and 4pπ [sup 3]Π[sub g] state, respectively, in [sup 20]Ne[sub 2] with corresponding values of 529.5, 9.75 cm[sup -1], and 567, 7.5 cm[sup -1] in [sup 22]Ne[sub 2]. The observed vibrational level differences [ΔG[sub (v+1/2)]-values] for the 4pπ [sup 3]Π[sub g] state are within 0.5% of analogous spacings for the ground electronic state (X [sup 2]Σ[sub u][SUP ARRANGE="STAGGER"]+]) of Ne[sub 2][SUP ARRANGE="STAGGER"]+] reported by Kim et al. [Phys. Rev. Lett. 68, 1311 (1992)]. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The X2Σ+1/2→B2Σ+1/2 absorption band of HgBr has been observed in the afterglow of a pulsed Ne-N2-HgBr2 discharge. Peaking in the ultraviolet (UV) near 350 nm, this continuum degrades slowly to the red and at 410 nm the absorption coefficient is 30% of its maximum value. Upon exciting the X→B band with an XeF (351 nm) or frequency tripled Nd:YAG (355 nm) laser, intense lasing is observed in the blue-green (λ∼502 nm). For λpump=351 nm, the energy conversion efficiency (UV to green) is 22% which corresponds to a photon conversion efficiency of 32%. The quantum efficiency for this four level system is 71%. [ABSTRACT FROM AUTHOR]

Results from new laser excitation spectra of 20Ne2 have been combined with previously published experimental and theoretical data to provide a consistent picture describing many of the Rydberg states observed below the first ionization limit. These states are found to fall mainly into Rydberg series converging on the ...3σu X 2Σ+u ground core of Ne+2. Spectral data for the npσ 3Σ+g←a 3Σ+u and npπ 3Πg←a 3Σ+u series support the current assignments of the upper states. Although (0–0) bands dominate these series, other vibronic transitions are observed. The 6–23pσ 3Σ+g–a(0–0) bands are more perturbed than the npπ 3Πg–a(0–0) series; hence, data for 4–17pπ 3Π+g–a(0–0) and 4–6fλ(3Σ+g,3Π+g)–a(0–0) were used to determine a value of 34 409±2 cm-1 for the lowest ionization limit of 20Ne2. Rotational constants for the v=0 levels of 4–17pπ 3Πg and 10–23pσ 3Σ+g also are presented. [ABSTRACT FROM AUTHOR]

Several Rydberg series attributable to transitions originating from the a 3Σ+u metastable state of the neon dimer have been observed by laser excitation spectroscopy in the afterglow of a pulsed corona discharge. The n=4–9 members of an npπ Πg←a (0–0) series have been rotationally resolved and the upper states characterized. The probable multiplicity of the Πg states is discussed. An unusual loss of intensity in the Q branches for the higher n member transitions and a weak perturbation between the v=1 vibrational level of the 5fσ 3Σ+g state and the 6pπ Πg, v=0 level are also reported. [ABSTRACT FROM AUTHOR]

Rotationally resolved, laser-induced fluorescence spectra for the transitions nf (3Σ+g,3Πg) ←a 3Σ+u (n=4–6) in Ne2 are presented and analyzed. The rotational structures of the upper states are found to be strongly l-uncoupled. Effective rotational constants for the a 3Σ+u, nfσ 3Σ+u, and nfπ 3Π±u states with n=4–6 are reported and the structures of the nf complexes discussed. [ABSTRACT FROM AUTHOR]

Arrays of microdischarge devices, 100 × 100 μm² in cross section, have been fabricated in a photodefinable glass, and electrically driven by interdigitated electrodes. Operated in Ne gas at pressures from 200 to 600 torr, 5 × 5 arrays of square microdise charge pixels are bright and draw a total current of 0.4-1.5 mA for direct current operating voltages of <200 V. [ABSTRACT FROM AUTHOR]

Electrical characteristics of arrays of (50 μm)² Si microplasma devices operating in 500-900 Torr of Ne are presented. Arrays as large as 200 × 200 pixels have been AC-excited at frequencies of 5-20 kHz and all exhibit reproducible ignition voltages and lifetimes. At 700 Torr, the power consumed per pixel for a 200 × 200 pixel array is 85 ± 2 μW, 190 ± 2 μW, and 290 ± 2 μW for excitation frequencies of 5, 10, and 15 kHz, respectively, and 5.5, 12.0, and 17.8 mA, respectively, of total current (RMS) drawn by the array. [ABSTRACT FROM AUTHOR]

Large arrays (up to 30×30) of microdischarge devices having separately addressable subarrays have been fabricated in Si and operated continuously in Ne, Ne/Ar, and Ne/Xe gas mixtures at pressures up to 800 Torr. Eight 3×3 arrays fabricated on the same substrate operate simultaneously at voltages as low as 210 V in 400 Torr of Ne and exhibit lifetimes beyond 19 h, or approximately 1 order of magnitude larger than those for earlier arrays in which all devices have a common anode. Four 15×15 arrays have also been tested and, when operated in Ne/Ar or Ne/10% Xe gas mixtures, generate intense fluorescence in the green from a phosphor over an area of 16 mm[sup 2]. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Flexible microdischarge arrays have been fabricated in metal-polymer-metal structures having a total thickness of ∼30 μm (∼1.2 mils). Composed of individual cylindrical devices having a diameter of 150 μm, positive differential resistance (30-120 kΩ), and operating voltages as low as 114 V for a 5 μm thick dielectric layer, the arrays operate at pressures beyond 700 Torr of Ne and in 1 atm of air. For Ne pressures ≤ 200 Torr, emission is produced from Ne ion excited states lying more than 55 eV above the neutral ground state (2p[sup 6]). The structures reported here are inexpensive to fabricate and have lifetimes beyond 50 h. Arrays that have been sealed by conventional lamination have also been operated successfully. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]