Share Email Print
cover

Proceedings Paper

Mid-IR Kerr-lens mode-locked polycrystalline Cr:ZnS and Cr:ZnSe lasers with intracavity frequency conversion via random quasi-phase-matching
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

Cr2+ doped ZnS and ZnSe possess a unique blend of physical, spectroscopic, and technological parameters. These laser materials feature ultra-broadband gain in 1.9 – 3.3 μm mid-IR range, low saturation intensities, and large pump absorption coefficients. The II-VI semiconductor hosts provide a low phonon cut-off, broad IR transparency, and high second and third order nonlinearity. Cr:ZnS and Cr:ZnSe are available in polycrystalline form: the material consists of a multitude of microscopic single-crystal grains with a broad distribution of grain sizes and orientations, which results in random quasi-phase-matching (RQPM). The distinctive features of RQPM are a linear dependence of the conversion yield with length of the medium and ultra-wide bandwidth of three-wave mixing. We review resent experimental results on optically pumped mid-IR ultrafast lasers based on polycrystalline Cr:ZnS and Cr:ZnSe. We demonstrate that Kerrlens mode-locking of polycrystalline Cr:ZnS and Cr:ZnSe lasers allow for generation of few-cycle mid-IR pulses with MW-level peak power. This opens several avenues for efficient nonlinear frequency conversion of short optical pulses directly in the laser gain medium via RQPM process. We implemented Kerr-lens mode-locked Cr:ZnS oscillators, which feature high power (up to 0.25 W), spectrally broad (up to 22 THz) second harmonic generation (SHG) in the laser medium. We also demonstrate simple and robust ultrafast source based on single-pass continuously pumped polycrystalline Cr:ZnS laser amplifier: mid-IR pulses with 6.8 W average power and the spectrum spanning 2.0–2.6 μm as well as SHG pulses with 0.52 W average power and 1.05 – 1.25 μm spectral span were obtained.

Paper Details

Date Published: 4 March 2016
PDF: 9 pages
Proc. SPIE 9731, Nonlinear Frequency Generation and Conversion: Materials, Devices, and Applications XV, 97310B (4 March 2016); doi: 10.1117/12.2218356
Show Author Affiliations
Sergey Vasilyev, IPG Photonics - Mid-Infrared Lasers (United States)
Igor Moskalev, IPG Photonics - Mid-Infrared Lasers (United States)
Mike Mirov, IPG Photonics - Mid-Infrared Lasers (United States)
Viktor Smolski, IPG Photonics - Mid-Infrared Lasers (United States)
Sergey Mirov, IPG Photonics - Mid-Infrared Lasers (United States)
The Univ. of Alabama at Birmingham (United States)
Valentin Gapontsev, IPG Photonics Corp. (United States)


Published in SPIE Proceedings Vol. 9731:
Nonlinear Frequency Generation and Conversion: Materials, Devices, and Applications XV
Konstantin L. Vodopyanov; Kenneth L. Schepler, Editor(s)

© SPIE. Terms of Use
Back to Top