Abstract: A manufacturing process is provided for fabrication of vertically coupled integrated photonic devices by projection lithographic technique. A multi-layered structure is formed which includes a pair of core waveguiding layers separated by a coupling interlayer and sandwiched between cladding layers. Prior to forming optical features in the core layers, alignment marks are etched completely through the whole multi-layered structure with the alignment marks being visible on both sides of the multi-layered structure to a conventional projection stepper. After the alignment marks are formed, a “bottom level” optical features are made through the bottom cladding layer, bottom core layer, and portion of intervening coupling layer. The formed sample is then bonded by a polymer to a carrier and a “top level” optical features are defined through the top cladding, top core layer, and portion of the intervening coupling layer.

Abstract: A manufacturing process is provided for fabrication of vertically coupled integrated photonic devices by projection lithographic technique. A multi-layered structure is formed which includes a pair of core waveguiding layers separated by a coupling interlayer and sandwiched between cladding layers. Prior to forming optical features in the core layers, alignment marks are etched completely through the whole multi-layered structure with the alignment marks being visible on both sides of the multi-layered structure to a conventional projection stepper. After the alignment marks are formed, a “bottom level” optical features are made through the bottom cladding layer, bottom core layer, and portion of intervening coupling layer. The formed sample is then bonded by a polymer to a carrier and a “top level” optical features are defined through the top cladding, top core layer, and portion of the intervening coupling layer.

Abstract: A semiconductor diode laser system with microwave mode locking. The system includes a semiconductor laser diode and an external reflector positioned to receive radiation that emits from the diode and reflects the same back into the diode, the microwave mode locking serving to modulate the radiation and the external reflector being properly positioned to return the radiation to the diode at a return time equal to the period of the drive signal or a submultiple thereof.