Abstract: A Fabry-Perot etalon is provided with first and second partially reflecting mirrors (12, 14) attached to a cuboidal spacer (16). The spacer (16) has a cylindrical bore (18) through its center and the mirrors (12, 14) are bonded, on axis, to opposite ends of this bore (18). Four support elements (22-28) are arranged symmetrically with respect to the axis in a tetrahedral configuration and constrain the cuboidal spacer (16) in all degrees of freedom. The cuboidal spacer (16) is flattened at its vertices, which results in modified distortion of the spacer (16) under the action of a compressive force acting through the supports. This structure of etalon provides insensitivity to inertial forces due to acceleration in all six degrees of freedom (three linear and three rotational) simultaneously with insensitivity to differential forces.

Abstract: A cyclic peptide (10) includes two domains (D1,D2), each including three charged sub-domains (14, 16). The first domain (D1) includes two anionic sub-domains (14) followed by a cationic sub-domain (16). The second domain (D2) includes two cationic sub-domains (16) followed by an anionic sub-domain (14). The two domains are connected to one another and separated by a tri-glycyl linker (12). The cyclic peptide (10) is able to self-assemble into a network able to mimic an extracelluar matrix, and which promotes cell growth whilst resisting biofilm formation.

Abstract: A maser assembly includes a pump light source; a maser material including molecules that are excited through the absorption of light (1) from the pump light source, and which subsequently transfer via intersystem crossing (9) into the sublevels of their triplet ground states, so causing a population inversion between two sublevels (16,18); an electromagnetic structure in which the masing material is disposed, and which supports a microwave mode that is both resonant in frequency with and magnetically coupled to the transition between these two sublevels; and where energy is supplied to the microwave mode through stimulated emission (25) across the transition at such a rate as to exceed the mode's electromagnetic losses, the microwave mode being a maser mode. The assembly includes provisions for effecting substantially continuous maser activity during operation of the assembly.

Abstract: A substrate includes a diffracting structure providing a hologram (20, 6). The diffracting structure encodes a holographic image so that thatholographic image is produced in response to reference light being incident on a major surface of the substrate at an angle of incidence with respect to the said major surface of the substrate, wherein the angle of incidence is no more than 20°.