Abstract: A uniform, smooth, non-puckering, clothlike, ultrasonic sealing friendly laminate suitable for use as a vacuum cleaner outer bag includes a web of meltblown polymer fibers, with a first nonwoven web formed of staple fibers bonded to one surface of the web of meltblown fibers and with a second nonwoven web formed of staple fibers bonded to the opposite surface of the web of meltblown fibers. The laminate includes an outermost layer of a printed knit textile fabric material laminated to the exposed outer surface of the second nonwoven web.

Abstract: An optical component of the integrated type is produced by coating a substrate (10) with a layer (12) of photo-polymerizable material which is substantially free of any thermal catalyst, exposing the layer to radiation at a first temperature via a mask for example so that zones of the layer are selectively polymerized in accordance with a predetermined pattern corresponding to the configuration of the desired optical component, heat treating the layer to post cure the polymerized zones, and thereafter flood illuminating the layer at a second temperature lower than the first to polymerize the previously unexposed areas. In this way, an enhanced refractive difference between the pattern and the surrounding areas can be achieved.

Abstract: For detecting changes in chemical or physical parameters an optical fibre core has bonded to its surface a chromophore responsive to the parameter. The core preferably has a porous surface with the chromophore coating extending into the porous structure.

Abstract: Apparatus for gathering data about a plurality of chemical or physical conditions, e.g. on industrial plants, utilizes a plurality of passive optical sensors. Light for the sensors is provided by a common broadband source, and distributed by an optical fiber from which light of a selected color is withdrawn for each sensor in turn, the color selected for each sensor being different from that selected for the other sensors. Each color is modified by its respective sensor as a function of changes in the conditions applied to the sensor, and all the modified colors are conveyed along a common data bus to be demultiplexed and the data displayed. The colors may be supplied by the data bus to detection means simultaneously or sequentially. Passive optical sensors avoid electrical interference and incendiary risks due to electrical sparking, and color multiplexing avoids difficulties associated with other forms of multiplexing in plant environments.

Abstract: Apparatus for measuring or detecting changes in a variety of physical or chemical parameters comprises an interferometer having a transmission frequency variable over a range of frequencies as a function of changes in the parameter. The transmission frequency is measured by beating with a coherent reference frequency.