Abstract: An remote fiber test system includes a non-blocking N.times.N optical switch having N input ports and N output ports with one of the input ports coupled to a measurement test instrument for examining any of the optical fibers coupled to the output ports. The non-blocking switch includes a plurality of N input mechanical optical switches and an plurality of N output mechanical optical switches with each of the input mechanical optical switches having an input optical transmission path representing one of the input ports and each of the output mechanical optical switches having an output optical transmission path representing one of the output ports. Each input mechanical optical switch has N output optical transmission paths which each optical transmission path being coupled to one of the input optical transmission paths of each of the output mechanical optical switches.

Abstract: A polarization insensitive optical attenuator (10,40) uses a polymer-dispersed liquid crystal (PDLC) film (14,56) to provide attenuation control over a wide range of attenuation values. The attenuator has a relatively low minimum attenuation and reliable light transmission with minimal insertion loss. The present invention is also adaptable for use with a temperature controller (200) that stabilizes the PDLC film, which promotes more uniform, predictable attenuation values.

Abstract: A protective passivation structure is provided for a thermal ink jet printing head which employs a resistive heating element formed of phosphorus-diffused silicon. The passivation structure includes a layer of silicon nitride over the heating element with a layer of silicon carbide over the silicon nitride layer. The nitride exhibits good adhesion to the underlying silicon as well as good thermal conductivity. The carbide has exceptionally good wear and hardness qualities against ink bubble cavitation as well as adhering well to the nitride.

Abstract: A spinner chuck having a recessed portion for receiving non-circular substrates is used to alleviate uneven build-up of photoresist coatings applied on the substrate. Openings are disposed in the base of the recess about the periphery thereof whereby to drain off coating material spun off into the volume between the substrate and chuck sidewall defining said recess.