Wavelength Division Multiplexing in Light Interface Technology.

The report describes the investigation and fabrication of a five channel wavelength division multiplex WDM optical communication link. The transmitter consists of five different wavelength Ga1-xAlxAs light emitting diodes LEDs and the receiver consists of five narrowband photodiodes PDs. The light is conducted from the transmitter to the receiver by a fiber optic bundle. Various techniques dichroic filters, furcated fiber bundle, and LED and PD plane arrays of coupling the light into and out of the fiber bundle are investigated. Measurements of receiver sensitivity, optical efficiency, and optical cross-coupling between channels were made. A theoretical analysis of the link optical efficiency and expected cross-coupling is performed and design information for future WDM optical links is established. It is also determined that fiber bundles which are classified as incoherent are, in general, quasi-coherent. It was necessary to incorporate optical mixing cylinders at the entrance and exit of the bundle to uniformly distribute the light throughout the cross-section. Author