Extended quasimodes within nominally localized random waveguides

We have measured the spatial and spectral dependence of the microwave field inside an open absorbing waveguide filled with randomly juxtaposed dielectric slabs in the spectral region in which the average level spacing exceeds the typical level width. Whenever lines overlap in the spectrum, the field exhibits multiple peaks within the sample. Only then is substantial energy found beyond the first half of the sample. When the spectrum throughout the sample is decomposed into a sum of Lorentzian lines plus a broad background, their central frequencies and widths are found to be essentially independent of position. Thus, this decomposition provides the electromagnetic quasimodes underlying the extended field in nominally localized samples. When the quasimodes overlap spectrally, they exhibit multiple peaks in space.Comment: 4 pages, submitted to PRL (23 December 2005

Intense plasma discharge source at 13.5 nm for extreme-ultraviolet lithography

Includes bibliographical references (page 36).We measured an emission of 6 mJ/pulse at 13.5 nm produced by the Li2+ Lyman-α transition excited by a fast capillary discharge, using a lithium hydride capillary. 75% of the energy emanated from a spot size of 0.6 mm. The emission is narrow band and would thus be useful in extreme-ultraviolet lithography imaging systems that use Mo:Si multilayer mirrors. The output within the bandwidth of Mo:Si mirrors was comparable with that of a laser-produced plasma (LPP), and the wall plug efficiency of 0.1% was nearly an order of magnitude better than that of a LPP

Signatures of photon localization

Signatures of photon localization are observed in a constellation of transport phenomena which reflect the transition from diffusive to localized waves. The dimensionless conductance, g, and the ratio of the typical spectral width and spacing of quasimodes, \delta, are key indicators of electronic and classical wave localization when inelastic processes are absent. However, these can no longer serve as localization parameters in absorbing samples since the affect of absorption depends upon the length of the trajectories of partial waves traversing the sample, which are superposed to create the scattered field. A robust determination of localization in the presence of absorption is found, however, in steady-state measurements of the statistics of radiation transmitted through random samples. This is captured in a single parameter, the variance of the total transmission normalized to its ensemble average value, which is equal to the degree of intensity correlation of the transmitted wave, \kappa. The intertwined effects of localization and absorption can also be disentangled in the time domain since all waves emerging from the sample at a fixed time delay from an exciting pulse, t, are suppressed equally by absorption. As a result, the relative weights of partial waves emerging from the sample, and hence the statistics of intensity fluctuations and correlation, and the suppression of propagation by weak localization are not changed by absorption, and manifest the growing impact of weak localization with t.Comment: RevTex 16 pages, 12 figures; to appear in special issue of J. Phys. A on quantum chaotic scatterin

UTA versus line emission for EUVL: Studies on xenon emission at the NIST EBIT

Spectra from xenon ions have been recorded at the NIST EBIT and the emission into a 2% bandwidth at 13.5 nm arising from 4d-5p transitions compared with that from 4d-4f and 4p-4d transitions in Xe XI and also with that obtained from the unresolved transition array (UTA) observed to peak just below 11 nm. It was found that an improvement of a factor of five could be gained in photon yield using the UTA rather than the 4d-5p emission. The results are compared with atomic structure calculations and imply that a significant gain in efficiency should be obtained using tin, in which the emission at 13.5 nm comes from a similar UTA, rather than xenon as an EUVL source material

Intense xenon capillary discharge extreme-ultraviolet source in the 10-16-nm-wavelength region

We have observed intense extreme-ultraviolet emission, within the 10-16-nm-wavelength range, emitted by a xenon capillary discharge plasma. Within a 0.3-nm bandwidth centered at 13.5 nm the axial emission intensity was comparable with that from the brightest laser-produced plasma sources, and a similar intensity was measured at approximately 11.3 nm. This source could thus be suitable for extreme-ultraviolet imaging applications, such as extreme-ultraviolet lithography. © 1998 Optical Society of America

Xenon-Emission-Spectra Identification In The 5-20-Nm Spectral Region In Highly Ionized Xenon Capillary-Discharge Plasmas

The emission from xenon capillary-discharge plasmas was studied. It was observed that three broadening band emission peaks dominate the spectrum in the 5-20-nm wavelength region. The results suggested that the emission within the broadband peak around 11 nm originates from transitions in more than one ion stage

Intense plasma discharge source at 13.5 nm for extreme-ultraviolet lithography

We measured an emission of 6 mJ/pulse at 13.5 nm produced by the Li2+ Lyman-α transition excited by a fast capillary discharge, using a lithium hydride capillary. 75% of the energy emanated from a spot size of 0.6 mm. The emission is narrow band and would thus be useful in extreme-ultraviolet lithography imaging systems that use Mo:Si multilayer mirrors. The output within the bandwidth of Mo:Si mirrors was comparable with that of a laser-produced plasma (LPP), and the wallplug efficiency of 0.1% was nearly an order of magnitude better than that of a LPP. © 1997 Optical Society of America