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Mach-Zehnder interferometry in a strongly driven superconducting qubit

Published in:
Sci., Vol. 310, No. 5754, 9 December 2005, pp. 1653-1657.
Topic:
R&D group:

Summary

We demonstrate Mach-Zehnder-type interferometry in a superconducting flux qubit. The qubit is a tunable artificial atom, the ground and excited states of which exhibit an avoided crossing. Strongly driving the qubit with harmonic excitation sweeps it through the avoided crossing two times per period. Because the induced Landau-Zener transitions act as coherent beamsplitters, the accumulated phase between transitions, which varies with microwave amplitude, results in quantum interference fringes for n = 1 to 20 photon transitions. The generalization of optical Mach-Zehnder interferometry, performed in qubit phase space, provides an alternative means to manipulate and characterize the qubit in the strongly driven regime.
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Summary

We demonstrate Mach-Zehnder-type interferometry in a superconducting flux qubit. The qubit is a tunable artificial atom, the ground and excited states of which exhibit an avoided crossing. Strongly driving the qubit with harmonic excitation sweeps it through the avoided crossing two times per period. Because the induced Landau-Zener transitions act...

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Nitride-based UV Geiger-Mode avalanche photodiodes

Published in:
2005 Int. Semiconductor Device Research Symp., 7-9 December 2005.

Summary

III-N materials currently enjoy a predominant role in the formation of solid-state light emitters for [lamda]
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Summary

III-N materials currently enjoy a predominant role in the formation of solid-state light emitters for [lamda]

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CMOS detector technology

Published in:
Exp. Astron., Vol. 19, No. 1-3, 2005, pp. 111-34.
Topic:

Summary

An entry level overview of state-of-the-art CMOS detector technology is presented. Operating principles and system architecture are explained in comparison to the well-established CCD technology, followed by a discussion of important benefits of modern CMOS-based detector arrays. A number of unique CMOS features including different shutter modes and scanning concepts are described. In addition, sub-field stitching is presented as a technique for producing very large imagers. After a brief introduction to the concept of monolithic CMOS sensors, hybrid detectors technology is introduced. A comparison of noise reduction methods for CMOS hybrids is presented. The final sections review CMOS fabrication processes for monolithic and vertically integrated image sensors.
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Summary

An entry level overview of state-of-the-art CMOS detector technology is presented. Operating principles and system architecture are explained in comparison to the well-established CCD technology, followed by a discussion of important benefits of modern CMOS-based detector arrays. A number of unique CMOS features including different shutter modes and scanning concepts...

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Design and testing of an all-digital readout integrated circuit for infrared focal plane arrays

Published in:
SPIE Vol. 5902. Focal Plane Arrays for Space Telescopes II, 3-4 August 2005, pp. 1-11.
Topic:

Summary

The digital focal plane array (DFPA) project demonstrates the enabling technologies necessary to build readout integrated circuits for very large infrared focal plane arrays (IR FPAs). Large and fast FPAs are needed for a new class of spectrally diverse sensors. Because of the requirement for high-resolution (low noise) sampling, and because of the sample rate needed for rapid acquisition of high-resolution spectra, it is highly desirable to perform analog-to-digital (A/D) conversion right at the pixel level. A dedicated A/D converter located under every pixel in a one-million-plus element array, and all-digital readout integrated circuits will enable multi- and hyper-spectral imaging systems with unprecedented spatial and spectral resolution and wide area coverage. DFPAs provide similar benefits to standard IR imaging systems as well. We have addressed the key enabling technologies for realizing the DFPA architecture in this work. Our effort concentrated on demonstrating a 60-micron footprint, 14-bit A/D converter and 2.5 Gbps, 16:1 digital multiplexer, the most basic components of the sensor. The silicon test chip was fabricated in a 0.18- micron CMOS process, and was designed to operate with HgxCd1-xTe detectors at cryogenic temperatures. Two A/D designs, one using static logic and one using dynamic logic, were built and tested for performance and power dissipation. Structures for evaluating the bit-error-rate of the multiplexer on-chip and through a differential output driver were implemented for a complete performance assessment. A unique IC probe card with fixtures to mount into an evacuated, closed-cycle helium dewar were also designed for testing up to 2.5 Gbps at temperatures as low as 50 K.
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Summary

The digital focal plane array (DFPA) project demonstrates the enabling technologies necessary to build readout integrated circuits for very large infrared focal plane arrays (IR FPAs). Large and fast FPAs are needed for a new class of spectrally diverse sensors. Because of the requirement for high-resolution (low noise) sampling, and...

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Megapixel CMOS image sensor fabricated in three-dimensional integrated circuit technology

Summary

In this paper a 3D integrated 1024x1024, 8um pixel visible image sensor fabricated with oxide-to-oxide wafer bonding and 2-um square 3-D-vias in every pixel is presented. The 150mm wafer technology integrates a low-leakage, deep-depletion, 100% fill factor photodiode layer to a 3.3-V, 0.35-um gate length fully depleted (FD) SOI CMOS readout circuit layer.
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Summary

In this paper a 3D integrated 1024x1024, 8um pixel visible image sensor fabricated with oxide-to-oxide wafer bonding and 2-um square 3-D-vias in every pixel is presented. The 150mm wafer technology integrates a low-leakage, deep-depletion, 100% fill factor photodiode layer to a 3.3-V, 0.35-um gate length fully depleted (FD) SOI CMOS...

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Design considerations for space-based radar phased arrays

Author:
Published in:
2005 IEEE MTT-S Int. Microwave Symp. Digest, 12-17 June 2005, pp. 1631-1634.

Summary

Space Based Radar (SBR) is being considered as a means to provide persistent global surveillance. In order to be effective, the SBR system must be capable of high area coverage rates, low minimum detectable velocities (MDV), accurate geolocation, high range resolution, and robustness against electronic interference. These objectives will impose challenging requirements on the antenna array, including wide-angle electronic scanning, wide instantaneous bandwidth, large poweraperture product, low sidelobe radiation patterns, lightweight deployable structures, multiple array phase centers, and adaptive pattern synthesis. This paper will discuss key enabling technologies for low earth orbit (LEO) SBR arrays including high efficiency transmit/receive modules and multilayer tile architectures, and the parametric influence of array design variables on the SBR system.
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Summary

Space Based Radar (SBR) is being considered as a means to provide persistent global surveillance. In order to be effective, the SBR system must be capable of high area coverage rates, low minimum detectable velocities (MDV), accurate geolocation, high range resolution, and robustness against electronic interference. These objectives will impose...

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Laser beam combining for high-power, high-radiance sources

Author:
Published in:
IEEE J. Sel. Top. Quantum Electron., Vol. 11, No. 3, May/June 2005, pp. 567-577.

Summary

Beam combining of laser arrays with high efficiency and good beam quality for power and radiance (brightness) scaling is a long-standing problem in laser technology. Recently, significant progress has been made usingwavelength (spectral) techniques and coherent (phased array) techniques, which has led to the demonstration of beam combining of a large semiconductor diode laser array (100 array elements) with near-diffraction-limited output (M2 ~ 1.3) at significant power (35 W). This paper provides an overview of progress in beam combining and highlights some of the tradeoffs among beam-combining techniques.
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Summary

Beam combining of laser arrays with high efficiency and good beam quality for power and radiance (brightness) scaling is a long-standing problem in laser technology. Recently, significant progress has been made usingwavelength (spectral) techniques and coherent (phased array) techniques, which has led to the demonstration of beam combining of a...

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Design considerations and results for an overlapped subarray radar antenna

Summary

Overlapped subarray networks produce flattopped sector patterns with low sidelobes that suppress grating lobes outside of the main beam of the subarray pattern. They are typically used in limited scan applications, where it is desired to minimize the number of controls required to steer the beam. However, the architecture of an overlapped subarray antenna includes many signal crossovers and a wide variation in splitting/combining ratios, which make it difficult to maintain required error tolerances. This paper presents the design considerations and results for an overlapped subarray radar antenna, including a custom subarray weighting function and the corresponding circuit design and fabrication. Measured pattern results will be shown for a prototype design compared with desired patterns.
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Summary

Overlapped subarray networks produce flattopped sector patterns with low sidelobes that suppress grating lobes outside of the main beam of the subarray pattern. They are typically used in limited scan applications, where it is desired to minimize the number of controls required to steer the beam. However, the architecture of...

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Nanocomposite approaches toward pellicles for 157-nm lithography

Published in:
J. Microlith., Microfab., Microsyst., Vol. 4, No. 1, January-March 2005, pp. 013004-1 - 013004-6.

Summary

Pellicle materials for use at 157 nm must display sufficient transparency at this wavelength and adequate lifetimes to be useful. We blended a leading candidate fluoropolymer with silica nanoparticles to examine the effect on both the transparency and lifetime of the pellicle. It is anticipated that these composite materials may increase the lifetime by perhaps quenching reactive species and/or by dilution, without severely decreasing the 157-nm transmission. Particles surface-modified with fluorinated moieties are also investigated. The additives are introduced as stable nanoparticle dispersions to casting solutions of the fluoropolymers. The properties of these solutions, films, and the radiationinduced darkening rates are reported. The latter are reduced in proportion to the dilution of the polymer, but there is no evidence that the nanoparticles act as radical scavengers.
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Summary

Pellicle materials for use at 157 nm must display sufficient transparency at this wavelength and adequate lifetimes to be useful. We blended a leading candidate fluoropolymer with silica nanoparticles to examine the effect on both the transparency and lifetime of the pellicle. It is anticipated that these composite materials may...

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Compact solid-state sources and their applications

Published in:
SPIE Vol. 5620, Solid State Laser Technologies and Femtosecond Phenomena, 25-28 October 2004, pp. 155-169.

Summary

Coherent solid-state optical sources based on Nd:YAG/Cr4+:YAG passively Q-switched microchip lasers cover the spectral range from 5000 to 200 nm, producing multikilohertz pulse trains with pulse durations as short as 100 ps and peak powers up to 1 MW. The wavelength diversity is achieved through harmonic conversion, parametric conversion, Raman conversion, and microchip-laser-pumped miniature gain-switched lasers. In all cases, the optical heads have been packaged in a volume of less than 0.5 liters. These compact, robust devices have the proven capability to take what were complicated laser-based experiments out of the laboratory and into the field, enabling applications in diverse areas. The short pulses are useful for high-precision ranging using time-of-flight techniques, with applications in 3-dimensional imaging, target identification, and robotics. The short pulse durations and ideal mode properties are also useful for material characterization. The high peak powers can be focused to photoablate material, with applications in laserinduced breakdown spectroscopy and micromachining. Ultraviolet systems have been used to perform fluorescence spectroscopy for applications including environmental monitoring and the detection of biological aerosols. Systems based on passively Q-switched microchip lasers, like the lasers themselves, are small, robust, and potentially low cost, making them ideally suited for field applications.
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Summary

Coherent solid-state optical sources based on Nd:YAG/Cr4+:YAG passively Q-switched microchip lasers cover the spectral range from 5000 to 200 nm, producing multikilohertz pulse trains with pulse durations as short as 100 ps and peak powers up to 1 MW. The wavelength diversity is achieved through harmonic conversion, parametric conversion, Raman...

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