Method for producing an impregnated waveguide

In a method of producing an optical glass waveguide comprising adding at least one dopant capable of varying the index of refraction to a porous glass matrix with interconnective pores by immersing the porous glass matrix in a liquid/solution of the dopant to impregnate the porous glass matrix with the solution, precipitating the dopant from the solution within the porous glass matrix in the porous glass matrix, removing solvent from the porous glass matrix and collapsing the porous glass matrix to a solid form, the improvement which comprises precipitating the dopant within the matrix before substantial evaporation of solvent, drying to remove solvent from the pores to obtain after the steps of collapsing the porous glass matrix to a solid form an optical glass waveguide.