Joseph P. Donnelly

Learn More
Water quality data on Se and Fe have been collected since April 2003 in a study area of the lower Arkansas River valley, Colorado. Data were obtained from 19 surface water locations and from 50 ground water monitoring wells using low-flow sampling techniques. GIS mapping and statistical analysis were used to characterize the occurrence, severity, and(More)
In this work, we modified our wafer-scale 3D integration technique, originally developed for Si, to hybridize InP-based image sensor arrays with Si readout circuits. InGaAs image arrays based on the InGaAs layer grown on InP substrates were fabricated in the same processing line as silicon-on-insulator (SOI) readout circuits. The finished 150-mm-diameter(More)
— We investigate the noise figure (NF) of high-power semiconductor InGaAsP optical amplifiers (SOAs) based on the slab-coupled optical waveguide (SCOW) concept having both ultralow optical confinement (∼ 0.5%) and low optical loss (α i ∼ 0.5 cm −1). At 1550 nm and 5-A current bias, the NF of SCOW amplifier (SCOWA) is 5.5 dB, and the small-signal gain and(More)
Citation Younger, Richard D. et al. " Crosstalk analysis of integrated Geiger-mode avalanche photodiode focal plane arrays. " Advanced Photon Counting Techniques III. Arrays of photon-counting Geiger-mode avalanche photodiodes (APDs) sensitive to 1.06 and 1.55 µm wavelengths and as large as 256 x 64 elements on 50 µm pitch have been fabricated for defense(More)
Keywords: A2. Metalorganic vapor phase epitaxy A3. Quantum wells A3. Semiconducting III–V materials B3. Heterojunction semiconducting devices B3. Quantum cascade lasers a b s t r a c t Strain-compensated (SC) GaInAs/AlInAs/InP multiple-quantum-well structures and quantum cascade lasers (QCLs) with strain levels of 1% and as high as 1.5% were grown by(More)
A slab-coupled optical waveguide laser is wavelength stabilized with a fiber Bragg grating and characterized under a narrow pulse high repetition rate direct modulation scheme suitable for efficient pulse position modulation format optical communication systems.
We present the first quantitative investigation of noise figure degradation in InGaAsP quantum-well semiconductor optical amplifiers at high bias. We compare two experimental measurements of population inversion factor for a 1.5-μm slab-coupled optical-waveguide amplifier (SCOWA).
• Hybrid and monolithic two-dimensional surface-emitting arrays of GaAs/AlGaAs diode lasers have been designed and fabricated. The hybrid devices consist oflinear arrays ofedge-emitting graded-index: separate-confinement-heterostructure singIe-quantum-well (GRIN-SCH-SQW) lasers mounted on a Si substrate containing integral 45° deflecting mirrors and(More)
  • 1