Calculation of refractive indices using Buchdahl's chromatic coordinate

In this paper we have completed an error analysis of the Buchdahl glass model for 813 glasses available from five manufacturers. A quadratic model has a standard deviation of 0.00002 and a maximum absolute error of 0.0001 in the visible spectral region. A cubic model has a standard deviation of 0.00005 and a maximum absolute error of 0.00026 over the full spectral region from 0.365 to 1.014 microm. A table giving the Buchdahl fitting coefficients for all the glasses, as well as the standard deviation and maximum error for each glass, is included for the quadratic model. The results indicate that the Buchdahl model is ideally suited for theoretical studies of refracting optical systems.