Low-cost optical sub-assemblies for metro access applications
The fiber optic communications industry is experiencing significant change as datacom 10 Gb/s Ethernet (10 GbE) networks merge with telecom SONET 10G networks in the drive to reach metro access applications. Lower data rate (1G Ethernet, 1G and 2G fiber channel, and SONET OC-48) applications have already merged to some extent as various versions are available within the SFF or SFP standard transceiver form factors. Traditional 10 Gb/s optical subassemblies (OSAs), developed for SONET OC-192 applications, used variations of the expensive butterfly type package. However, smaller form factor modules (such as the XFP that uses SFF optical connectors and LC duplex optical connectors) require much smaller OSAs. To meet the size limitation of packaging 10G OSAs into the XFP transceiver and also meet the 10 GbE market challenge of providing low-cost solutions, new 10 Gb/s OSA components are needed.
A novel low-cost small-form-factor transceiver module
A key trend in the optoelectronic data-communication industry is the move towards lower cost and smaller transceivers. This trend has driven transceiver modules to the Small-Form-Factor (SFF) dimensions, requiring SFF optical connectors, resulting in a cost lower than their larger predecessors (for example GBICs or 1/spl times/9 transceivers based on the larger duplex SC optical connector). The design and implementation of a low-cost SFF fiber optic transceiver based on the SFF LC fiber optic connector is discussed. Since most of the transceiver cost is associated with the optical subassemblies (OSAs), low cost, yet smaller OSAs are required. In addition, the entire transceiver assembly has been optimized for cost reduction by using direct-chip-attach electronics, and surface-mount components all mounted on a single card that snaps into a plastic-molded retainer. These SFF LC transceivers are well suited for Gigabit Ethernet, Fibre Channel, and 1394b applications, along with other applications requiring low cost data transfer at data rates of 1.25 Gb/s to 2.125 Gb/s, or higher.
Variations common to the interplanetary magnetic field, the zonal atmospheric circulation and the earth's rotation
A study of the cyclic fluctuations in the earth's rotation, the geomagnetic field, the global atmospheric circulation and solar activity reveals the existence of 50-day and 120-day oscillations common to all. Our results, as well as the results obtained by radiometric measurements from the satellites Nimbus-7 and the Solar Maximum Mission (Wilson 1982; Pap 1985), suggest that their origin lies in the physical processes in the sun. The mechanism remains unexplained but from this work it follows that the role of the interplanetary magnetic field could very well be important.