Study of the growth of infrared-transparent non-spheric layer lenses by continuous-wave laser deposition

The fabrication of non-spheric microns-thick layer lenses by continuous-wave laser deposition has been monitored by using an interferometric method. An infrared-transparent amorphous chalcogenide alloy has been used as base material. Results evidence the thermodynamic nature of this laser-assisted deposition process, with two distinct stages occurring in the deposition rates, namely, a first induction stage with thickness increasing at non-constant rate, and a second steady-state stage with thickness increasing at constant rate. The deposition process has been shown to be reproducible and it allows the tailoring of the thickness profile for promising fabrication of non-spheric layer lenses and free-form optics.

► Fabrication of non-spheric layer lenses by continuous-wave laser deposition. ► Infrared-transmitting base material used. ► Monitoring of the fabrication process by interferometric method. ► Results reproducible and promising for tailoring the thickness profile. ► Potential fabrication of free-form optics by this method.