Abstract: An integrated optical package comprises an integrated optical device within a casing, an optical fiber coupled with the device and following a curved path, the fiber being supported by a substantially rigid conduit at least between an interior wall of the casing and the coupling with the optical device. This relieves stress which would otherwise be exerted by the fiber. It is preferred that the conduit has a C-section thereby to support the fiber therewithin. Alternatively, the conduit can comprise two fitting parts which when fitted together form a closed conduit such as an annular section. The conduit can be molded of a plastics material. The conduit can be snug with the fiber and hence supported thereby.

Abstract: Applicant's unique method provides for the use of a single piece of transfer tape for multiple transfers, with the transfer tape being forgiving, clear, having a high shelf life, and being non-self destructive. Such a method has been heretofore unavailable.

Abstract: The polarizer is formed on a silicon rib waveguide (4) having an upper face and two side faces, and comprises a section of the silicon rib waveguide (4) with a buffer layer (6) and a light absorbing layer (7) on either the upper face of the rib or at least one side face of the rib. The buffer layer (6) has a refractive index similar to that of the waveguide (4) such that light traveling along the waveguide (4) and incident upon the respective face thereof passes into the buffer layer (6) and then into the light absorbing layer (7) so either the TM (transverse magnetic) or TE (transverse electric) mode of the light traveling along the waveguide is attenuated.

Abstract: A process for making a silicon rib wavegide structure is described comporising the following steps:(i) forming a window in a protective layer on the surface of a silicon wafer to expose a part of said surface;(ii) depositing a buffer layer at least over said exposed surface;(iii) carrying out an etch step to etch the buffer layer and silicon outside a protected rib portion thereby to form a silicon rib with the buffer layer on its upper surface; and(iv) forming a layer of cladding at least on side walls of the silicon rib.

Abstract: An axial flow compressor with an inner casing and an outer casing. The inner casing has bleed apertures. The outer casing is provided with loading devices which are positioned adjacent to the bleed apertures such that the loading devices apply loads on the inner casing in the vicinity of the bleed apertures. Components of the loads applied by the loading devices are arranged to oppose and preferably balance any loads applied on the inner casing due to the bleed apertures' releasing the pressure differential across the inner casing. The loading devices comprise cylinders secured to the inner casing and pistons secured to the outer casing to form chambers. The chambers are supplied with fluid at a predetermined pressure. The loading devices oppose undesirable local reductions in clearance between static shrouds and the rotor blades.

Abstract: The casings of gas turbine engines are subject to loadings which distort the casing and adversely affect the running clearance between rotating and static components contained within the casings. The invention provides an engine having inner and outer housings the inner housing containing one of the engine compressors. The inner casing is mounted on a load transmitting and isolating structure which allows thrust and torque to be transmitted to the outer casing, but isolates the inner casing from distortions of the outer casing. The load transmitting and isolating structure includes a torque reaction and mounting means at the upstream end of the inner casing, a mounting means and a thrust reacting means mounted between the ends of the inner casing. The mounting means are adjacent the bearings of the rotor shaft of the compressor and are not affected to any appreciable extent by outer casing distortion.

Abstract: The invention concerns the use of 5-hydroxy-3-thiazolidine-2-thiones of the structure I ##STR1## where R.sub.1 =(CHOH).sub.m, R.sub.2 =(CHOH).sub.n where (m+n)=0 to 6, and R.sub.3 is alkyl or hydroxy-alkyl as depressants in the flotation of mixtures of base metal minerals, particularly those containing molybdenum, copper, lead, zinc; and to flotation processes using these compounds.