Deliverables Bistable micromechanical fibre switches and switch arrays Summary: A new type of optical fibre switch based on silicon micromachining has been developed. The aim was to develop a low-cost protection switch that can easily be fabricated in rows. A bistable concept guarantees long term stability and the use of butt fibre coupling results in low insertion losses below 2 dB (including MT-connector losses) and very low cross talk (less than -60 dB). The new fabrication process allows the integration of thermals actuators and highly accurate fibre alignment grooves on a single silicon substrate with 3 mask levels, only. An advanced bulk micromachining process is used to fabricate silicon actuators at the boundary to precision mechanics with very high accuracy. The two actuators - a bidirectional in-plane actuator for fibre movement and a vertical platform actuator for fibre clamping - are both driven by thermal expansion of indirectly heated silicon cantilevers. Within the project also arrays of 12 switches were fabricated and housed together with a microcontroller interface for actuator timing. This new type shows a new fabrication technology for fibre-optical components which can be extended to further applications like 2x2 and 1x4 switches, attenuators or other components that require moving-fibre components. Implementation of a configuration and fault management platform for optical networks Summary: A management platform has been developed and implemented to oversee and ensure the correct behaviour of an optical network. This platform has a hierarchical structure and uses the SNMP protocol. The creation of this new platform has involved the specific definition of the Management Information Base (MIBs) for an optical network as well as the definition and implementation of the needed management facilities. A Graphical User Interface allows the human manager to perform configuration management operations such as establishment and clear down of a channel, access to the local databases and direct interaction with the hardware. An alarm processing algorithm has been developed at the CPN level to perform the fault management. This algorithm filters the received alarms and forwards the result of the algorithm to the global manager. Development of planar SiON waveguide technology with high-refractive index contrast A new planar waveguide technology with high refractive index contrast of 0.05 has been developed based on siliconoxynitride (SiON) layers deposited by PECVD. Waveguide bends with radii as low as 1.5 mm were realized using this technology. Complex devices which are not feasible by using the standard waveguide technology with the conventional low index contrast of 0.005 - 0.009 can now be realized with practical chip dimensions. In contrast to the standard glass-on-silicon technology with Ge-, Ti-, or P-dopants our technology uses SiON waveguide core layers sandwiched between silicon dioxide cladding layers and grown on silicon substrates, and allows us to adjust the refractive index contrast to considerably higher values. During the course of the project major improvements have been made. The propagation losses were reduced to values as low as 0.1 dB/cm, the optical birefringence was minimized to 1 x 10-4, and waveguide bends with a radii of 1.5 mm and very small excess losses were achieved. This high index contrast waveguide technology opens the route to future low-cost mass production of integrated waveguide devices with different functionalities for optical communication systems. It is ideally suited to realize complex device designs and very compact devices in a cost-effective way. Planar lightwave circuits in SiON high refractive index technology A wavelength tunable, polarization insensitive finite impulse response (FIR) filter subsystem for application in WDM optical networks was developed. The filter chip is based on a cascade of resonant couplers and was realized in a compact way using the newly developed high index contrast planar SiON waveguide technology. Various filter functions can be realized. E.g as a specific WDM-add/drop filter one can add and drop one wavelength channel out of a stream of up to 12 WDM channels. The add/drop wavelength can be tuned using the thermo-optic effect via chromium heaters to any desired wavelength in the free spectral range of the filter device. Several main technical achievements were demonstrated during the last years. An add-after-drop configuration was implemented and a 1-from-4 channel filter device with greatly improved isolation figures between the add and the drop port was built and used in the COBNET field trial. The newly developed individual heater concept allows one to improve the spectral shape of the filter and to tune the filter to the desired wavelength. A complete add/drop subsystem was built by developing a box housing a redundant pair of add/drop filters, the driving circuits for the heaters and a single board computer for control and reconfiguration by network management. Exploitable results Concept and technology for Corporate Optical Backbone Networks (COBNET) COBNET has developed the architectural concepts and corresponding technological components for future corporate backbone networks based on wavelength-division and optical space-division add/drop ring technology. A field trial encompassing two interconnected customer premises networks validates the results. The architecture for future corporate backbone networks proposed by COBNET incorporates both wavelength-division multiplexed (WDM) add/drop rings for use as a backbone for large customer premises and corporate metropolitan area networks and, secondly, fibre ribbon-based space-division multiplexed (SDM) add/drop rings for use inside large corporate buildings and between neighbouring buildings. Failure protection is provided in conjunction with a network management framework. In order to meet the requirements of the cost-sensitive private network market, cost-improved technological components have been developed for COBNET such as WDM lasers, SDM laser arrays, receivers and receiver arrays, clear-channel retiming chips, optical protection switches, planar WDM (de)multiplexers and add/drop filters. A field trial validates the results which incorporates two rings of each kind located on two distant sites. Project URL : http://lrcwww.epfl.ch/COBNET/ Searching for OpenAIRE data... 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