| 摘要 |
The invention relates to photonic crystals, i.e. three-dimensional dielectric structures (2) which are impervious to electromagnetic radiation within a given wavelength irrespective of the direction of incidence. An inventive photonic crystal comprises, for instance, a maxtrix-type arrangement of free-standing dielectric micro-columns or cylinders (4) having very small diameters. Said micro-columns or cylinders are placed on a substrate (3) whose thermal expansion coefficient between 60 °C and 85 °C is at least 50 % lower than the thermal expansion coefficients of quartz glass, thereby enabling the thermal expansion of the substrate to be kept to a minimum even when high temperature variations occur; whereby the distance (d) between the micro-columns supported by the substrate or the microcyinders of the photonic crystal varies only to a small amount, whereby the optical characteristics are essentially more stable than those of photonic crystals with a quartz glass substrate. Preferably, glass ceramics or, for example, Zerodur(R) are used as a substrate. |
