COMPOSITE OPTICAL MATERIALS. USES OF COMPOSITE OPTICAL MATERIALS AND METHODS FOR THE MANUFACTURE OF COMPOSITE OPTICAL MATERIALS

摘要

A thermochromic composite optical body formed of a composite optical material. The material has a three dimensionally periodic arrangement of particles of a first material having refractive index n1 disposed in a matrix of a second material, different to the first material, having refractive index n2. The material is capable of being modified by an external stimulus to provide an optical effect based on the three dimensionally periodic arrangement of particles. At a first condition of the external stimulus, the body is substantially transparent and satisfies at least one of: formula (1) and ?n 1 and n2 at the first condition of the external stimulus. nva is the volume average refractive index of the body at the first condition of the external stimulus, ? is a wavelength of light corresponding to the three dimensionally periodic arrangement of particles. L is the thickness of the body at the first condition of the external stimulus. At a second condition of the external stimulus, different from the first condition, the body provides a colour effect due to a corresponding change in n1 and/or n2.