**Acknowledgements**

The results of comparisons of calculated and measured effective refractive indices confirm the effectiveness of the method of control of the diffusion processes. It is based on the best possible determined temperature dependence of the diffusion coefficients of exchanged ions for the given glass-admixture system. The described method allows to guarantee the repeatability of

This method can also be used to control the production of two- and three-dimensional

 1.4816 1.4812 0.0004 1.4820 1.4817 0.0003 1.4825 1.4833 0.0008 1.4775 1.4771 0.0004 1.4783 1.4779 0.0004 1.4792 1.4795 0.0003 1.4742 1.4738 0.0004 1.4753 1.4749 0.0004 1.4766 1.4766 0.0000 1.4714 1.4710 0.0004 1.4727 1.4723 0.0004 1.4742 1.4741 0.0001 1.4691 1.4689 0.0002 1.4705 1.4700 0.0005 1.4721 1.4719 0.0002 1.4687 1.4684 0.0003 1.4703 1.4700 0.0003 1.4688 1.4686 0.0002 **Short time diffusion processes**

**tdiff = 21h, Tave = 275.6°C tdiff = 23h, Tave = 281.1°C tdiff = 22h, Tave = 292.1°C Ncalc Nmeas |Ncalc Nmeas| Ncalc Nmeas |Ncalc Nmeas| Ncalc Nmeas |Ncalc Nmeas|**

**tdiff = 3h, Tave = 286°C tdiff = 2.9h, Tave = 287°C tdiff = 1h, Tave = 289°C Ncalc Nmeas |Ncalc Nmeas| Ncalc Nmeas |Ncalc Nmeas| Ncalc Nmeas |Ncalc Nmeas|**

↔ Na<sup>+</sup>

. Source of admixture ions: AgNO3. *λ* = 677 nm,

in the

0 1.4780 1.4777 0.0003 1.4781 1.4791 0.0010 1.4750 1.4742 0.0008

The chapter presents selected aspects of the ion exchange in glass processes in terms of changes in the refractive index. The processes of electrodiffusion doping of soda-lime glass with Ag+ ions have been described. Such processes, which are carried out with a change of polarization of the electric field, enable the production of refraction changes of the glass with refractive index profile of various characters. Using the electrodiffusion processes with a fixed polari‐ zation of electric field, the equilibrium concentration of mobile ions in the glass was estimated. These results were confirmed by a method based on glass substrates weighing before and after the diffusion process. The results of experimental studies of stress birefringence in BK-7 glass doped with potassium ions K+ were also presented. Ion exchange processes K+ ↔ Na<sup>+</sup>

glass were carried out during more than 500 h. It also presents the results of changes of these

1 1.4713 1.4714 0.0001 1.4713 1.4718 0.0005

**Table 9.** Diffusion processes in Pyrex glass. Ion exchange Ag+

effective refractive indices at the level of ΔN ~10-3.

structures in gradient glasses.

134 Ion Exchange - Studies and Applications

**m**

**m**

polarization TE.

**6. Conclusions**

This chapter was financed from the funds of the National Science Centre, awarded on the basis of the decision DEC-2011/01/B/ST7/06525.
