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Quantum Electronics, IEEE Journal of

Issue 1 • Date Jan. 2006

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Displaying Results 1 - 13 of 13
  • Table of contents

    Page(s): 1
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    Freely Available from IEEE
  • Guest Editorial

    Page(s): 3
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    Freely Available from IEEE
  • High repetition rate collisional soft X-ray lasers based on grazing incidence pumping

    Page(s): 4 - 13
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (864 KB) |  | HTML iconHTML  

    We discuss the demonstration of gain-saturated high repetition rate table-top soft X-ray lasers producing microwatt average powers at wavelengths ranging from 13.9 to 33 nm. The results were obtained heating a precreated plasma with a picosecond optical laser pulse impinging at grazing incidence onto a precreated plasma. This pumping geometry increases the energy deposition efficiency of the pump beam into the gain region, making it possible to saturate soft X-ray lasers in this wavelength range with a short pulse pump energy of only 1 J at 800-nm wavelength. Results corresponding to 5-Hz repetition rate operation of gain-saturated 14.7-nm Ni-like Pd and 32.6-nm line Ne-like Ti lasers pumped by a table-top Ti:sapphire laser are reported. We also discuss results obtained using a 1 ω1054-nm prepulse and 2 ω527-nm short pulse from a Nd:glass pump laser. This work demonstrates the feasibility of producing compact high average power soft X-ray lasers for applications. View full abstract»

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  • Phase-matching techniques for coherent soft X-ray generation

    Page(s): 14 - 26
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (640 KB) |  | HTML iconHTML  

    Coherent beams at soft X-ray (SXR) wavelengths can be generated using extreme nonlinear optics by focusing an intense laser into a gas. In this paper, we discuss phase-matching and quasi-phase-matching techniques that use gas-filled modulated waveguides to enhance the frequency conversion process. This leads to the generation of SXR beams that are both spatially and temporally coherent. View full abstract»

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  • Specialized electron beam nanolithography for EUV and X-ray diffractive optics

    Page(s): 27 - 35
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2336 KB)  

    Diffraction of electromagnetic radiation remains a viable method for manipulation and focusing of extreme ultraviolet and X-ray wavelengths where the optical properties preclude significant phase shift without attenuation. As the wavelength becomes smaller, the characteristic dimensions needed for effective utilization of diffraction proportionally shrink, placing significant demands on the half-pitch of the diffractive structure. State-of-the-art nanofabrication technology is then required. Additionally, line placement over the entire grating, zone plate lens, or other diffractive element requires an accuracy on the order of a small fraction of a linewidth over the entire structure. This places a heavy burden on the alignment and calibration of the pattern-generating tool. In the case of zone plate lenses, smooth curved geometric elements are required. Specialized techniques for electron beam lithography have been developed to meet these demands, which diverge from the technology used to meet the challenges encountered in mask making and electronic circuit research. The techniques are in four areas: on axis calibration, beam placement, subpixel image processing for overlay, and smooth generation of arc shapes. Using the ensemble of these specialized techniques, high-resolution electron beam lithography nanofabrication has been used to successfully make diffractive structures with linewidths approaching 10 nm and near diffraction limited optical performance. View full abstract»

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  • Studies of magnetic microstructures with soft X-ray transmission microscopy

    Page(s): 36 - 43
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (6064 KB) |  | HTML iconHTML  

    We review recent achievements of magnetic full-field soft X-ray transmission microscopy. This technique allows for an element-specific imaging of magnetic domain structures in thin films and nanopatterned elements. With a lateral resolution down to 15 nm, the ability to record images in external magnetic fields and the application of stroboscopic pump-and-probe schemes detailed insights into fundamental mechanisms of micromagnetism can be obtained which are relevant in the development of high density and ultrafast magnetic storage and sensor technologies. View full abstract»

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  • Extreme ultraviolet lithography capabilities at the advanced light source using a 0.3-NA optic

    Page(s): 44 - 50
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2920 KB)  

    Extreme ultraviolet lithography is a leading candidate for volume production of nanoelectronics at the 32-nm node and beyond. In order to ensure adequate maturity of the technology by the start date for the 32-nm node, advanced development tools are required today with numerical apertures of 0.25 or larger. In order to meet these development needs, a microexposure tool based on SEMATECH's 0.3-numerical aperture microfield optic has been developed and implemented at Lawrence Berkeley National Laboratory, Berkeley, CA. Here we describe the Berkeley exposure tool in detail, discuss its characterization, and summarize printing results obtained over the past year. Limited by the availability of ultrahigh resolution chemically amplified resists, present resolving capabilities limits are approximately 32 nm for equal lines and spaces and 28 nm for semi-isolated lines. View full abstract»

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  • Photoresponse of (In,Ga)N-GaN multiple-quantum-well structures in the visible and UVA ranges

    Page(s): 51 - 58
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (432 KB) |  | HTML iconHTML  

    Characterization and analysis of photoresponse in p-n diodes with embedded (In,Ga)N-GaN multiple-quantum-well (MQW) structures are reported. Their dependence on the number of wells and In composition are considered. The influence of device structure on electric fields in the active region and on device responsivity has also been studied. Theoretical considerations as well as photocapacitance and photocurrent measurements show that the position of quantum wells (QWs), either in the quasi-neutral region or in the space charge region, is a critical factor in the collection efficiency. Hence, device photoresponse is not proportional to the number of QWs in photovoltaic mode. Present p-MQW-n devices show a promising performance as UVA and visible photodetectors, with detectivities, D*, higher than 1.2×1012 cm·Hz12/·W-1 and rejection ratios higher than 103. View full abstract»

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  • Analysis of mode characteristics for deformed square resonators by FDTD technique

    Page(s): 59 - 63
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (480 KB) |  | HTML iconHTML  

    The mode frequencies and quality factors (Q-factors) in two-dimensional (2-D) deformed square resonators are analyzed by finite-difference time-domain (FDTD) technique. The results show that the deformed square cavities with circular and cut corners have larger Q-factors than the perfect ones at certain conditions. For a square cavity with side length of 2 μm and refractive index of 3.2, the mode Q-factor can increase 13 times as the perfect corners are replaced by a quarter of circle with radius of 0.3 μm. Furthermore the blue shift with the increasing deformations is found as a result of the reduction in effective resonator area. In square cavities with periodic roughness at sidewalls which maintains the symmetry of the square, the Q-factors of the whispering gallery (WG)-like modes are still one order of magnitude larger that those of non-WG-like modes. However, the Q-factors of these two types of modes are of the same order in the square cavity with random roughness. We also find that the rectangular and rhombic deformation largely reduce the Q -factors with the increasing offset and cause the splitting of the doubly degenerate modes due to the breaking of certain symmetry properties. View full abstract»

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  • A comparative study of higher order Bragg gratings: coupled-mode theory versus mode expansion modeling

    Page(s): 64 - 70
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (232 KB) |  | HTML iconHTML  

    The modal reflectivity and loss of lamellar diffraction gratings to be used in distributed-feedback and distributed-Bragg reflector lasers were computed in dependence of wavelength, duty cycle and Bragg order. Different methods based on the approximate coupled-mode theory and and the exact bidirectional mode expansion modeling were compared and a good mutual agreement was found. The slab Green's function needed to compute the coupling coefficients can be approximated by that of a homogeneous unbounded medium with sufficient accuracy. View full abstract»

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  • Supersonic chemical oxygen-iodine laser with X-shaped streamwise vortex Generator

    Page(s): 71 - 77
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (640 KB) |  | HTML iconHTML  

    High-throughput operation of a supersonic chemical oxygen-iodine laser (COIL) is achieved with an advanced mixing nozzle. The mixing nozzle consists of a staggered arrangement of thin wedges lying across the flow duct, and looks like the letter "X" when it is viewed from the side. A 32.9% chemical efficiency is measured experimentally with this nozzle and buffer-gas precooling. Computational fluid dynamics (CFD) calculations are conducted to understand the rapid mixing capability of the nozzle. A series of streamwise vortices generated by the alternating wedges greatly enhances the mixing process in the supersonic stream and the rapid formation of the gain medium. The temperature and Mach number of the flow field are estimated from the gain-profile measurement of the I (2P12/) to I (2P32/) transition. Good agreement with the CFD calculations is seen. View full abstract»

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  • Highly efficient Raman frequency converter with strontium tungstate crystal

    Page(s): 78 - 84
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (272 KB) |  | HTML iconHTML  

    A highly efficient extracavity Raman laser pumped by the infrared nanosecond laser pulses is presented utilizing the recently recommended Raman medium-strontium tungstate crystal (SrWO4). The maximum conversion efficiency of the first and second Stokes pulses both reached about 50%, and the maximum total conversion efficiency of the first and second Stokes was obtained to be 70% in the experiment. The conversion efficiency dependence on the polarization and the temporal characteristics of the Stokes and pump pulses were also studied. A theoretical model for the solid-state extracavity Raman laser was established based on the radiation transfer equations describing stimulated Raman scattering processes, and solved numerically. This model can accurately predict the energy transfer dynamics observed in extracavity Raman lasers. View full abstract»

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Aims & Scope

The IEEE Journal of Quantum Electronics is dedicated to the publication of manuscripts reporting novel experimental or theoretical results in the broad field of the science and technology of quantum electronics..

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Aaron R. Hawkins
Brigham Young University