Publications
Gadolinium oxide coated fully depleted silicon-on-insulator transistors for thermal neutron dosimetry
Summary
Summary
Fully depleted silicon-on-insulator transistors coated with gadolinium oxide are shown to be effective thermal neutron dosimeters. The theoretical neutron detection efficiency is calculated to be higher for Gd2O3 than for other practical converter materials. Proof-of-concept dosimeter devices were fabricated and tested during thermal neutron irradiation. The transistor current changes linearly...
Etching selectivity of indium tin oxide to photoresist in high density chlorine- and ethylene-containing plasmas
Summary
Summary
Etching of indium tin oxide (ITO) thin films in high density chlorine plasmas is studied, with the goal of increasing the etching selectivity to photoresist. The ITO etching rate increases with ethylene addition, but is not affected by BCl3 addition. ITO exhibits a threshold energy for ion etching, whereas the...
Reconfigurable RF systems using commercially available digital capacitor arrays
Summary
Summary
Various RF circuit blocks implemented by using commercially available MEMS digital capacitor arrays are presented for reconfigurable RF systems. The designed circuit blocks are impedance-matching network, tunable bandpass filter, and VSWR sensor. The frequency range of the designed circuits is 0.4-4GHz. The MEMS digital capacitor arrays that are employed in...
High-power arrays of quantum cascade laser master-oscillator power-amplifiers
Summary
Summary
We report on multi-wavelength arrays of master-oscillator power-amplifier quantum cascade lasers operating at wavelengths between 9.2 and 9.8 um. All elements of the high-performance array feature longitudinal (spectral) as well as transverse single-mode emission at peak powers between 2.7 and 10 W at room temperature. The performance of two arrays...
Nonlinear bleaching, absorption, and scattering of 532-nm-irradiated plasmonic nanoparticles
Summary
Summary
Single-pulse irradiation of Au and Ag suspensions of nanospheres and nanodisks with 532-nm 4-ns pulses has identified complex optical nonlinearities while minimizing material damage. For all materials tested, we observe competition between saturable absorption (SA) and reverse SA (RSA), with RSA behavior dominating for intensities above ~50 MW/cm^2. Due to...
Development of adaptive liquid microlenses and microlens arrays
Summary
Summary
We report on the development of sub-millimeter size adaptive liquid microlenses and microlens arrays using two immiscible liquids to form individual lenses. Microlenses and microlens arrays having aperture diameters as small as 50 microns were fabricated on a planar quartz substrate using patterned hydrophobic/hydrophilic regions. Liquid lenses were formed by...
Measurement of the surface-enhanced coherent anti-Stokes Raman scattering (SECARS) due to the 1574 cm^-1 surface-enhanced Raman scattering (SERS) mode of benzenethiol using low-power (<20 mW) CW diode lasers
Summary
Summary
The surface-enhanced coherent anti-Stokes Raman scattering (SECARS) from a self-assembled monolayer (SAM) of benzenethiol on a silver-coated surface-enhanced Raman scattering (SERS) substrate has been measured for the 1574 cm^-1 SERS mode. A value of 9.6 +- 1.7 x 10^-14 W was determined for the resonant component of the SECARS signal...
Improving quantum gate fidelities by using a qubit to measure microwave pulse distortions
Summary
Summary
We present a new method for determining pulse imperfections and improving the single-gate fidelity in a superconducting qubit. By applying consecutive positive and negative pi pulses, we amplify the qubit evolution due to microwave pulse distortions, which causes the qubit state to rotate around an axis perpendicular to the intended...
Time-reversal symmetry and universal conductance fluctuations in a driven two-level system
Summary
Summary
In the presence of time-reversal symmetry, quantum interference gives strong corrections to the electric conductivity of disordered systems. The self-interference of an electron wave function traveling time-reversed paths leads to effects such as weak localization and universal conductance fluctuations. Here, we investigate the effects of broken time-reversal symmetry in a...
Atomic layer deposition of Sc2O3 for passivating AlGaN/GaN high electron mobility transistor devices
Summary
Summary
Polycrystalline, partially epitaxial Sc2O3 films were grown on AlGaN/GaN substrates by atomic layer deposition (ALD). With this ALD Sc2O3 film as the insulator layer, the Sc2O3/AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors showed excellent electrical performance with a high Ion/Ioff ratio of over 108 and a low subthreshold slope of 75...