Abstract: An analytical cell including a lightguide with a plurality of conduits filled with a migration medium. The medium, the lightguide and a surrounding medium have refractive indices selected such that light entering the lightguide is internally reflected within the lightguide to provide substantially uniform illumination of the conduits.

Abstract: A light exposure system is used to expose an alignment layer formed of anistropically absorbing molecules so as to allow alignment of subsequently applied liquid crystal polymer (LCP) molecules. The light incident on the alignment layer is polarized. When a single polarizer is used, the azimuthal polarization direction varies across the substrate carrying the alignment layer. Various approaches to reducing the azimuthal polarization variation may be adopted, including the introduction of various types of polarization rotation reduction element and in selecting an appropriate tilt angle for the light source. Furthermore, a reflective structure may be inserted between the light source and the alignment layer. Use of the reflective structure increases the total amount of light incident on the alignment layer.

Abstract: A light-guide light (1) suitable for use in illuminated displays and signs comprises a housing (3) defining an optical cavity having first and second generally parallel major faces (5, 6), and a light source (11) positioned to direct light into the optical cavity from one side. The first major face (5) comprises a material (for example, a prismatic film) having coefficients of reflection and transmission that vary with the angle at which light is incident on the material. The second major face (6) comprises a narrow-scattering reflective material having a reflectance of at least 85%, for example a highly-efficient reflective material provided with a suitable textured pattern.