THE REFLECTIVE PROPERTIES OF BROAD-BAND OPTICAL MULTILAYERS

Binary multilayers with a certain kind of disorder may exhibit high re flection range over a very wide bandwidth. The dependencies of this ba ndwidth on the center wavelength, random layers sequence, refractive c ontrast of the coating materials, layer thickness errors and the angle of incidence have been studied numerically. Our simulations have show n that broadband reflectors can be designed for various applications. The reflective curves for staggered multilayers are also computed. The results show that the broadening effect of irregular multilayers is d ominated by its degree of disorder. A broadband TiO2-SiO2 multilayer i s fabricated. The measured width of the transmittance less than 1% for this multilayer covers 400 nm, from 700 to 1100 nm, which is just the tuning range of T-i:sapphire lasers.