Abstract: A process for providing a protection against damages in a machine head is claimed. The process comprises the following steps: First a blind steel plate (protection plate 20) is fixed to a protection chamber (10). Then the transparent liquid jet (WJ) guided laser beam (LB) is started, which drills a transit-hole into it. This protection plate (20) has the transit-hole (23) precisely arranged on the optical axis. Therefore no further alignment is required. Further an apparatus for treating a work piece by means of a laser beam (LB) which is guided in a transparent liquid jet (WJ) is claimed. The apparatus comprises a protection chamber (10) mounted on the output (5) of a coupling unit (CU) and a protection plate (20) replaceable fixed to the first chamber (10) protecting the outlet (15) of the first chamber (10) from sputtered debris.

Abstract: A process for providing a protection against damages in a machine head, wherein the machine head launches a transparent liquid jet guided laser beam LB by means of a nozzle 3 along an optical axis for treating a work piece is claimed. The process comprises the following steps: First a blind steel plate (protection plate 20) is fixed to a front of a protection chamber (10) prior to the liquid water jet (WJ). Then the transparent liquid jet (WJ) guided laser beam (LB) is stared, which impinges on the blind steel plate (20) blank and drills a transit-hole into the blind steel plate blank. The transit-hole (23) has a size which substantially corresponds to a cross-section of the laser beam (LB) guiding transparent liquid jet (WJ). The steel plate (20) with the transit-hole (23) provides a protection plate (20) having the transit-hole (23) precisely arranged on the optical axis. Therefore no further alignment is required.

Abstract: Apparatus for demultiplexing a wavelength division multiplexed optical signal comprising a plurality of signals each having a different wavelength. The apparatus comprises a demultiplexer sub-assembly and a multi-channel receiver optical sub-assembly. The demultiplexer sub-assembly comprises a filter block sub-assembly for splitting the input optical signal. The receiver optical sub-assembly comprises an array of photo detectors for converting the optical signals from the filter block sub-assembly into electrical signals. The electrical signals are amplified by amplifier ICs and transmitted through electrical leads. The demultiplexer sub-assembly and the multi-channel receiver optical sub-assembly are actively aligned and fixed together.

Abstract: Apparatus for demultiplexing a wavelength division multiplexed optical signal comprising a plurality of signals each having a different wavelength. The apparatus comprises a demultiplexer sub-assembly and a multi-channel receiver optical sub-assembly. The demultiplexer sub-assembly comprises a filter block sub-assembly for splitting the input optical signal. The receiver optical sub-assembly comprises an array of photo detectors for converting the optical signals from the filter block sub-assembly into electrical signals. The electrical signals are amplified by amplifier ICs and transmitted through electrical leads. The demultiplexer sub-assembly and the multi-channel receiver optical sub-assembly are actively aligned and fixed together.

Abstract: A tunable Fabry-Perot vertical cavity photonic device and a method of its fabrication are presented. The device comprises top and bottom semiconductor DBR stacks and a tunable air-gap cavity therebetween. The air-gap cavity is formed within a recess in a spacer above the bottom DBR stack. The top DBR stack is carried by a supporting structure in a region thereof located above a central region of the recess, while a region of the supporting structure above the recess and outside the DBR stack presents a membrane deflectable by the application of a tuning voltage to the device contacts.

Abstract: A tunable Fabry-Perot vertical cavity photonic device and a method of its fabrication are presented. The device comprises top and bottom semiconductor DBR stacks anid a tunable air-gap cavity therebetween. The air-gap cavity is formed within a recess in a spacer above the bottom DBR stack. The top DBR stack is carried by a supporting structure in a region thereof located above a central region of the recess, while a region of the supporting structure above the recess and outside the DBR stack presents a membrane deflectable by the application of a tuning voltage to the device contacts.

Abstract: A tunable Fabry-Perot vertical cavity photonic device and a method of its fabrication are presented. The device comprises top and bottom semiconductor DBR stacks and a tunable air-gap cavity therebetween. The air-gap cavity is formed within a recess in a spacer above the bottom DBR stack. The top DBR stack is carried by a supporting structure in a region thereof located above a central region of the recess, while a region of the supporting structure above the recess and outside the DBR stack presents a membrane deflectable by the application of a tuning voltage to the device contacts.

Abstract: A tunable Fabry-Perot vertical cavity photonic device and a method of its fabrication are presented. The device comprises top and bottom semiconductor DBR stacks and a tunable air-gap cavity therebetween. The air-gap cavity is formed within a recess in a spacer above the bottom DBR stack. The top DBR stack is carried by a supporting structure in a region thereof located above a central region of the recess, while a region of the supporting structure above the recess and outside the DBR stack presents a membrane deflectable by the application of a tuning voltage to the device contacts.