BROWSE
Detail
Journal Article
Femtosecond Mid-IR Cr:ZnS Laser with Transmitting Graphene-ZnSe Saturable Absorber
- Authors
- Won Bae Cho, Ji Eun Bae, Seong Cheol Lee, Nosoung Myoung, Fabian Rotermund
- Issue Date
- 2023-12
- Citation
- Current Optics and Photonics, v.7, no.6, pp.738-744
- ISSN
- 2508-7266
- Publisher
- Optical Society of Korea
- Language
- English
- Type
- Journal Article
- Abstract
- Graphene-based saturable absorbers (SAs) are widely used as laser mode-lockers at various laser oscillators. In particular, transmission-type graphene-SAs with ultrabroad spectral coverage are typically manufactured on transparent substrates with low nonlinearity to minimize the effects on the oscillators. Here, we developed two types of transmitting graphene SAs based on CaF2 and ZnSe. Using the graphene-SA based on CaF2, a passively mode-locked mid-infrared Cr:ZnS laser delivers relatively long 540 fs pulses with a maximum output power of up to 760 mW. In the negative net cavity dispersion regime, the pulse width was not reduced further by inhomogeneous group delay dispersion (GDD) compensation. In the same laser cavity, we replaced only the graphene-SA based on CaF2 with the SA based on ZnSe. Due to the additional self-phase modulation effect induced by the ZnSe substrate with high nonlinearity, the stably mode-locked Cr:ZnS laser produced Fourier transform-limited ~130 fs near 2,340 nm. In the stable single-pulse operation regime, average output powers up to 635 mW at 234 MHz repetition rates were achieved. To our knowledge, this is the first attempt to achieve shorter pulse widths from a polycrystalline Cr:ZnS laser by utilizing the graphene deposited on the substrate with high nonlinearity.
- KSP Keywords
- 40 nm, Group delay dispersion, High nonlinearity, Laser cavity, Laser oscillator, Mid-IR, Mid-infrared(MIR), Passively mode-locked, Single-pulse, Transmission-type, Transparent substrate
This work is distributed under the term of Creative Commons License (CCL)
(CC BY NC)
(CC BY NC)
