Today’s article

term: ambigel

Determination:

product of aqueous or organic gel (alcogel) drying at atmospheric pressure, characterised, in contrast to xerogel, by low densities approaching the density of aerogels.

Description:

The ambigel production process usually involves consecutive solvent exchange from polar to nonpolar, hydrophobisation of surface or additional strengthening of a solid structure and a special program of drying at a low heating rate. ...

Today’s picture

distributed feedback laser

Determination:

injection semiconductor laser, in which the feedback is produced by light waves reflection from a periodic lattice generated in the active medium.

Description:

In the injection heterolasers with distributed feedback (DFB lasers) to create a feedback one of the heterointerfaces is corrugated, which creates a periodic variation in the refractive index and leads to an interference reflection (see Fig.). The lattice period  ...