| abstract |
The invention provides a process for making a gradient index optical element having a precisely parabolic configuration of refractive index profile. After a concentration profile is imparted across a gel prepared by a sol-gel technique, the concentration profile is fixed. In this case, the treatment with a concentration profile-fixing solution is carried out at a temperature higher than that at which the treatment with a concentration profile-imparting solution is carried out, whereby the rate of fixing the concentration profile is so higher than that of imparting the concentration profile, so that any possible deformation of the concentration profile formed at the concentration profile-imparting step is reduced or inhibited. |