Valentin Gapontsev

Valentin Gapontsev (1939-2021) was founder and chief executive officer of IPG Photonics (Oxford, MA).

FIGURE 1. The progress of ultrafast mid-IR Cr:ZnS/ZnSe oscillators based on different mode-locking methods is compared: SESAM (squares), graphene (diamonds), Kerr-lens (circles), and by type of the gain medium: single-crystal (open symbols) and polycrystalline (solid symbols). Arrows show the record parameters obtained to date (based on the data published in references 1 and 2 and the most current results obtained at IPG Photonics).
Lasers & Sources

Mid-IR Lasers: Kerr-lens mode-locking in polycrystalline Cr:ZnS and Cr:ZnSe competes with Ti:sapphire

May 5, 2015
Kerr-lens mode-locking of polycrystalline chromium-doped zinc sulfide and zinc selenide leads to multiwatt output power, pulse durations approaching three optical cycles, and ...
FIGURE 1. Materials-processing applications fall into specific domains when placed in a map of power at the workpiece vs. the beam quality, or beam parameter product (BPP). For the 1060- to 1080-nm range, BBP is approximately found from the conventional M2 beam-quality parameter by multiplying by 0.3 (a diffraction-limited 1-æm-emitting laser will have M2=1 and BPP = 0.3 mm-mrad). This map assumes that the laser beam is focused on the workpiece with an f/4 optic. Laser sources are also shown as points; all applications lying above and to the left of a source's BPP and power values can be addressed by that source.
Fiber Optics

Fiber lasers grow in power

Aug. 1, 2002
The fiber laser has a history almost as long as that of the laser itself.