Towards high power broad-band OPCPA at 3000 nm
Abstract
High-energy femtosecond laser pulses in the mid-infrared (MIR) wavelength range are essential for a wide range of applications from strong-field physics to selectively pump and probe low energy excitations in condensed matter and molecular vibrations. Here we report a four stage optical parametric chirped pulse amplifier (OPCPA) which generates ultrashort pulses at a central wavelength of 3000 nm with 430 $\mu$J energy per pulse at a bandwidth of 490 nm. Broadband emission of a Ti:sapphire oscillator seeds synchronously the four OPCPA stages at 800 nm and the pump line at 1030 nm. The first stage amplifies the 800 nm pulses in BBO using a non-collinear configuration. The second stage converts the wavelength to 1560 nm using difference frequency generation in BBO in a collinear geometry. The third stage amplifies this idler frequency non-collinearly in KTA. Finally, the fourth stage generates the 3000 nm radiation in a collinear configuration in LiIO$_3$ due the broad amplification bandwidth this crystal provides. We compress these pulses to 65 fs by transmission through sapphire. Quantitative calculations of the individual non-linear processes in all stages verify that our OPCPA architecture operates close to optimum efficiency at minimum absorption losses, which suggests that this particular design is very suitable for operation a high average power at multi kHz repetition rates.
- Publication:
-
Optics Express
- Pub Date:
- October 2019
- DOI:
- 10.1364/OE.27.031330
- arXiv:
- arXiv:1908.01879
- Bibcode:
- 2019OExpr..2731330B
- Keywords:
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- Physics - Optics
- E-Print:
- 6 figures