Frederick G. Johnson

Learn More
Vertically coupled microring resonator channel-dropping filters are demonstrated in the GaInAsP-InP material system. These devices were fabricated without regrowth. In this method, low-loss single-mode waveguides are removed from the growth substrate and bonded to a GaAs transfer substrate with benzocyclobutene. This permits fabrication of vertically(More)
In an ecological study of the distribution of self-injury in London, Canada, the authors found that self-injury occurred more frequently in the central areas of the city. Multivariate analysis revealed that living arrangements, such as high density of housing and single-person households, are closely associated with inflated rates on self-injury. Low(More)
We show how Newton’s rings manifest themselves in near-field scanning optical microscopy and discuss how this effect can be used with topographic imaging to measure correlated roughness of thin films. In conventional optics, transmission through a thin nonabsorbing film depends on film thickness when multiple reflections from the film boundaries are(More)
A new optical packet switching network and its enabling technologies are investigated for implementation in a Petaflops scale supercomputer system. We capitalize on the immense bandwidth of the optical fiber interconnects by deploying WDM/TDM packet payloads. To accommodate current optical switching technologies, the routing operations in the network are(More)