Abstract: An optical device comprising: at least one liquid crystal cell comprising liquid crystal material in a cell gap having a dimension at least partly defined by spacers, the liquid crystal cell comprising electrodes for inducing substantially confocal refractive index patterns in substantially concentric, first regions of the liquid crystal material; and within an area bound by an outer edge of an outermost one of the first regions, the spacers being at least disproportionately located in one or more re-set regions between the first regions.

Abstract: A technique, comprising: producing an assembly in preparation for a later process of permanently stretching one or more parts of the assembly; wherein the assembly comprises an amount of liquid crystal material in a region laterally bounded by a lateral barrier; and wherein producing the assembly comprises determining the amount of LC material, based at least partly on one or more parameters of the later stretching process.

Abstract: A technique, comprising: producing an assembly in preparation for a later process of permanently stretching one or more parts of the assembly; wherein the assembly comprises an amount of liquid crystal material in a region laterally bounded by a lateral barrier; and wherein producing the assembly comprises determining the amount of LC material, based at least partly on one or more parameters of the later stretching process.

Abstract: A technique of producing a liquid crystal device, comprising: providing a cell assembly comprising a liquid crystal material contained directly between (i) a polariser component comprising an active film and no more than one support film, and (ii) a first control component including a stack of layers defining electrical control circuitry; and containing further liquid crystal material directly between the polariser component of the assembly and another control component including another stack of layers defining electrical control circuitry.

Abstract: A fluorescence quenching immunoassay method includes determining the presence or concentration of an analyte in a liquid sample in dependence upon quenching of an autofluorescence signal of a substrate. Devices for conducting the fluorescence quenching immunoassay method are also described.

Abstract: A device for optically exciting fluorescence is disclosed. The device comprises transparent substrate having first and second opposite faces and a multilayer stack disposed on the second face of the substrate. The multilayer stack comprises a first layer having first and second opposite faces and a first refractive index and a second layer having first and second opposite faces and a second refractive index. The first face of the first layer is disposed on the second face of the substrate. The first face of the second layer is disposed on the second face of the first layer such that the first layer is interposed between the second layer and the substrate. The substrate has a third refractive index. The first refractive index is less than the second refractive index and the third refractive index. The device comprises a light source carried by the first face of the substrate and arranged to emit light towards the first face of the first layer.

Abstract: A technique of producing a liquid crystal device, comprising: providing a cell assembly comprising a liquid crystal material contained directly between (i) a polariser component comprising an active film and no more than one support film, and (ii) a first control component including a stack of layers defining electrical control circuitry; and containing further liquid crystal material directly between the polariser component of the assembly and another control component including another stack of layers defining electrical control circuitry.

Abstract: A technique, comprising: assembling together two liquid crystal half-cells; wherein at least one of the two half-cells comprises a support film and an array of spacer structures formed in situ on the support film; and wherein the assembling comprises pressing together the two half-cells with pre-prepared spacer elements dispensed onto at least one of the two half-cells over at least an area shared with the array of spacer structures; wherein the spacer elements provide primary control of the size of a cell gap between the two half-cells, and the spacer structures function to resist compression of the spacer elements.

Abstract: An analytical test device (12) includes one or more light emitters (13) configured to emit light within a first range of wavelengths (??a). The analytical test device (12) also includes one or more first photodetectors (14), each first photodetector (14) being sensitive to a second range of wavelengths (??b) around a first wavelength. The analytical test device (12) also includes one or more second photodetectors (15), each second photodetector (15) being sensitive to a third range of wavelengths (??c) around a second wavelength, the second wavelength being different to the first wavelength. The analytical test device (12) also includes a correction module (16) configured to receive signals (19, 20) from the first and second photodetectors (14, 15) and to generate a corrected signal (21) based on a weighted difference of the signals (19, 20) from the first and second photodetectors (14, 15).

Abstract: A lateral flow device is disclosed. The device comprises a test layer comprising a test region between opposite first and second end regions of the test layer, a first permeable layer having a first contact area in contact with the first end region, and a second permeable layer having a second contact area in contact with the first end region. The device further comprises a first non-permeable layer between the first and second permeable layers and having a third contact area with the first end region. The first contact area and the second contact area are separated by the third contact area. The device further comprises a sample pad in fluid contact with the first and second permeable layers for delivery of a sample fluid to the first and second contact regions. The second contact area is further from the second end region than the first contact area is from the second end region.

Abstract: Apparatus for optically exciting fluorescence and detecting light is disclosed. The apparatus comprises a device for optically exciting fluorescence. The device comprises a transparent substrate having first and second opposite faces and a multilayer stack disposed on the second face of the substrate. The multilayer stack comprises a first layer having first and second opposite faces and a first refractive index and a second layer having first and second opposite faces and a second refractive index. The first face of the first layer is disposed on the second face of the substrate. The first face of the second layer is disposed on the second face of the first layer such that the first layer is interposed between the second layer and the substrate. The substrate has a third refractive index. The first refractive index is less than the second refractive index and the third refractive index.

Abstract: An analytical test device (i) includes two or more sets of emitters (2, 3, 98, 101), each set of emitters (2, 3, 98, 101) comprising one or more light emitters (2, 3, 98, 101) configured to emit light within a range around a corresponding wavelength. Each set of light emitters (2, 3, 98, 101) is configured to be independently illuminable. The test device (1) also includes one or more photodetectors (4) arranged such that light from each set of emitters (2, 3, 98, 101) reaches the photodetectors (4) via an optical path (7) comprising a sample receiving portion (8). The emitters (2, 3, 98, 101) and photodetectors (4) are configured such that, at the sample receiving portion (8) of the optical path (7), a normalised spatial intensity profile generated by each set of emitters (2, 3, 98, 101) is substantially equal to a normalised spatial intensity profile generated by each other set of emitters (2, 3, 98, 101).

Abstract: A device for optically exciting fluorescence is disclosed. The device comprises transparent substrate having first and second opposite faces and a multilayer stack disposed on the second face of the substrate. The multilayer stack comprises a first layer having first and second opposite faces and a first refractive index and a second layer having first and second opposite faces and a second refractive index. The first face of the first layer is disposed on the second face of the substrate. The first face of the second layer is disposed on the second face of the first layer such that the first layer is interposed between the second layer and the substrate. The substrate has a third refractive index. The first refractive index is less than the second refractive index and the third refractive index. The device comprises a light source carried by the first face of the substrate and arranged to emit light towards the first face of the first layer.

Abstract: A device for performing Raman spectroscopy is disclosed. The device comprises a sensor device comprising a transparent substrate having first and second opposite faces. The sensor device comprises a light source, a first grating, a first reflective element, and a light detector carried by the first face of the substrate. The light source is arranged to emit light towards the second face of the substrate and the light detector is directed at the second face of the substrate. The first grating is interposed between the light source and the light detector. The first reflective element is interposed between the light source and the first grating. The sensor device comprises a second grating and a second reflective element carried by the second face of the substrate, the second grating arranged to receive light from the light source and the second reflective element arranged to receive light from the first grating.