Peculiarities of the formation of planar micro-optic elements on porous glass substrates under the effect of laser radiation followed by sintering

Local laser-induced change of optical properties in the bulk of photochromic porous silicate glass doped by silver and copper halides

“…An important part in the development and implementation of these laser technologies is assigned to optically transparent materials, where MAs are formed, for example, high silica porous glass (PG) [5,6]. It was shown in [7][8][9][10] that the formation of MAs of various shapes and sizes is possible in a bulk PG plate with the use of laser radiation, including a continuous laser with an emission wavelength which is weakly absorbed by PG. The high transmittance of PG plates in an optical wavelength range [11], their transformation to quartzoid glass upon sintering in furnace [12,13], and the possibility of retention of MAs in PG plates on sintering [8] give reasons to sug gest that this material is promising for the formation of MAs.…”

“…It was shown in [7][8][9][10] that the formation of MAs of various shapes and sizes is possible in a bulk PG plate with the use of laser radiation, including a continuous laser with an emission wavelength which is weakly absorbed by PG. The high transmittance of PG plates in an optical wavelength range [11], their transformation to quartzoid glass upon sintering in furnace [12,13], and the possibility of retention of MAs in PG plates on sintering [8] give reasons to sug gest that this material is promising for the formation of MAs. The unique adsorption properties of this glass allow their consecutive impregnation in aqueous solu tions of silver and copper nitrates and, after that, in the mixture of alkali metal halides (two steps), as a result of which a high silica vitreous material with photo chromic properties is obtained, the photochromic porous glass (PCPG) [14][15][16][17][18].…”

Laser induced structural changes in porous glass due to hot and cold compaction

“…Experimental data on thermally compacted regions -MR, formed by CO 2 -laser radiation on the surface of PG plates, and the experimental data on the size change of the MR and the PG plates during sintering are presented in [11] (Fig. 3).…”

“…This process is related to, above all, the presence of fine silica inside the pores in the glass and To preserve the properties of the MR, above all, the optical properties, it is proposed in [11] that a PG plate with a MR be sintered in a furnace up to the transformation of the PG plate into a quartzoid. It is also shown that the quartzoid region -a MR formed with rapid by laser radiation and rapid cooling -can be preserved by sintering the PG, and in addition the conditions under which a MR can be preserved are determined.…”

“…The heating of PG due to the absorption of laser radiation within the interaction region results in hot compaction, i.e., transformation into quartzoid and, correspondingly, the formation of a quartzoid MR. Such a MR surrounds a so-called transitional layer, whose porosity varies evenly from zero in the MR to that of the PG plate [10,11]. The dimensions and shape of the thermally compacted region can be set by changing the parameters of the laser radiation (intensity, focusing spot size, scan rate during ruling).…”