Studies of single-mode injection lasers and of quaternary materials. Volume 2: Measurement of electro-optic effects in InGaAsP junction waveguides

Both the linear electro-optic (Pockel's) effect and electroabsorption (Franz-Keldysh effect) in waveguiding junctions of InGaAsP were measured. The electro-optic coefficient is found to be 0.1-0.14x10 to the -12 power m/V at lambda = 1.54 - 1.65 micrometers. Possibly this is the first reported measurement of the electro-optic coefficient for InGaAsP. The value found for the electroabsorption is on the order of 7x10 to the -4 power cm to the -1 power/(V/cm) or approximately 100 cm/1 for fields of 200,000 V/cm at lambda 1.3 micrometers. All measurements were made on a quaternary film with a bandgap wavelength of 1.23 micrometers. Because of the rapid commercial introduction of quaternary lasers, LEDs, and detectors to take advantage of large optical fiber bandwidths and low losses in the 1.2- to 1.7- micrometer region, these measurements are significant in providing some of the basic physical constants needed to design modulators and switches capable of operating at microwave frequencies in this wavelength region

Optical Backplane Interconnect Technology (OBIT)

We describe and analyze a novel approach to implementing an Optical Backplane Interconnect Technology (OBIT) that is capable of optically connecting any row of a 32x32 backplane array to any row of a second 32x32 array. Each backplane array is formed monolithically on a wafer. The technology is based on the use of Grating Surface Emitting (GSE) waveguides formed on a wafer containing quantum-well and separate confinement waveguide layers. These layers are used for transverse guiding, gain, modulation, detection, and for the formation of wavelength tunable distributed-Bragg reflector lasers. The required surface structures are formed photolithographically. The GSE waveguides act as efficient antennae that radiate light at angles selected by tuning the wavelength of the lasers. The same waveguides may be used as the receiving antennae when the array is used in the receiving mode. Thus, wavelength tuning is used to direct each row of the transmitting array to the desired row of the receiving array. In summary: The optical backplane array will have the following characteristics: Any row of a 32x32 GSE array may be optically connected to any row of a second 32x32 array. Only one switch decision is required to switch 32 parallel connections to any one of 32 positions. Each monolithic array can be used as both transmitter and receiver by switching the bias on the quantum-well switch-detectors. Separate transmitting and receiving structures could be provided for duplex operation. For a bit error rate of 10 sup 9 at 100-MHz data rate, a required laser power of 12 mW is calculated based on an estimated total optical loss of 40 dB

A Copernican View of Health Care Antitrust

Sage and Hammer use the analogy of Copernican astronomy to suggest that understanding the dramatic change wrought by managed care requires a conceptual reorientation regarding the meaning of competition in health care and its appropriate legal and regulatory oversight. Both share the belief that misperceiving the world limits potential for technical and social progress

Nucleon Vector Strangeness Form Factors: Multi-pion Continuum and the OZI Rule

We estimate the 3 \pi continuum contribution to the nucleon strange quark vector current form factors, including the effect of a 3 \pi \rho \pi resonance. We find the magnitude of this OZI-violating contribution to be comparable to that of typical OZI-allowed contributions. We also study the isoscalar electromagnetic form factors, and find that the presence of a \rho \pi resonance in the multi-pion continuum may generate an appreciable contribution.Comment: 18 pages, LaTex, 4 PS figures, uses epsf.sty, rotate.sty, revised to include 3\pi -> \omega resonance and e^+ e^- dat

Nonfamily Abducted Children: National Estimates and Characteristics.

Presents national estimates of children abducted by nonfamily perpetrators, based on surveys of households and law enforcement agencies. The Bulletin, which is part of a series summarizing findings from the Second National Incidence Studies of Missing, Abducted, Runaway, and Thrownaway Children (NISMART–2), also analyzes characteristics of victims, perpetrators, and episodes. During the study period, an estimated 58,200 children were abducted by nonfamily perpetrators; 115 were victims of stereotypical kidnappings. Teenagers were the most frequent victims. Nearly half of all victims were sexually assaulted. In 40 percent of stereotypical kidnappings, the child was killed; in another 4 percent, the child was not recovered. The Bulletin also discusses policy implications of the findings

Children Abducted by Family Members: National Estimates and Characteristics.

Presents national estimates of children abducted by family members in 1999, their demographic characteristics, and the characteristics of perpetrators and episodes. The Bulletin is part of a series summarizing findings from the second National Incidence Studies of Missing, Abducted, Runaway, and Thrownaway Children (NISMART-2). Of the estimated 203,900 children who experienced a family abduction, 117,200 were classified as caretaker missing and 56,500 were reported as missing to law enforcement or other agencies. Younger children were at greatest risk of being abducted by a family member. Use of threats or physical force was uncommon. The Bulletin also discusses policy implications of the findings

Sexually Assaulted Children: National Estimates and Characteristics.

Provides information on the estimated number and characteristics of children who were sexually assaulted in the United States in 1999. This Bulletin is the seventh in the Second National Incidence Studies of Missing, Abducted, Runaway, and Thrownaway Children (NISMART–2) series. Information on sexual assault was gathered from NISMART–2 interviews with victims and their families