| abstract |
An optical material is a mixture of materials comprising a first material having a refractive index of not more than 1.45 for the d-line and a second material having an Abbe's number, indicating wavelength dispersion in the visible region, of not more than 25. A relation between the refractive index for the d-line (nd) and the Abbe's number (nud) is defined as follows:nd<=-6.667x10<-3>nud+1.70. |