Vertical-cavity surface-emitting lasers and smart pixels for optical interconnection systems
Though TDM (and recently WDM) are generally adopted to increase the total throughput in optical communication systems, SDM must be more effective in most optical interconnection systems. This is because SDM has more advantage in cost and power consumption than TDM, when the transmission distance is rather short, i.e. less than a few hundred meters. VCSEL and smart pixel arrays are very important for constructing optical interconnection systems because they can emit, switch and process a number of broadband optical signals simultaneously. This paper reviews VCSELs and VCSEL-based smart pixels, and discusses the issues for their application to optical interconnections. VCSELs and smart pixels are applicable to three types of parallel optical interconnections: 1) parallel optical fiber link-the optical signals from the SEL array are transmitted through a fiber ribbon for distances less than a few hundred meters; 2) free-space optical interconnects-high-density optical signals from a two-dimensional SEL array are distributed into several ports for distance shorter than one meter; 3) reconfigurable optical interconnects nterconnect patterns among processors are changed dynamically by means of free-space photonic switching networks.
Laterally oxidized long wavelength CW vertical- cavity lasers
Vertical-cavity lasers (VCLs) operating at 1.3 and 1.55 µm wavelengths are potentially low cost sources for optical communications.
A slowly rotating coil system for AC field measurements of Fermilab Booster correctors
A method for measurement of rapidly changing magnetic fields has been developed and applied to the testing of new room temperature corrector packages designed for the Fermilab Booster Synchrotron. The method is based on fast digitization of a slowly rotating tangential coil probe, with analysis combining the measured coil voltages across a set of successive magnet current cycles. This paper presents results on the field quality measured for the normal and skew dipole, quadrupole, and sextupole elements in several of these corrector packages.