The general scheme for L2-DUHA is shown below; the seed for the 100 TW pulse train and the auxiliary output are both generated via supercontinuum in YAG crystals. The continuum is stretched to 2 ps and amplified via OPCPA with the picosecond pulse output of a 2 kHz Yb:YAG thin disk regenerative amplifier. The 820 nm seed for the 100 TW amplifier is stretched in an Offner Stretcher to 1.5 ns. The stretched pulses are then amplified via high energy OPCPA up to 4 J and compressed.
The pump laser for the high energy OPCPA is a diode pumped cryogenically cooled Yb:YAG multi-slab laser. The aggressive cooling and multi-slab crystal geometry allow the laser to work at very high average powers before suffering from deleterious thermal effects. For the first part of the project the laser will run at 20 Hz; then, after an upgrade to the pump laser head, the repetition rate will be increased to 50 Hz.
| Parameter | Target 2024 | Target 2026 |
| Energy | 2 J | 3 J |
| Pulse Duration | 25 fs | 25 fs |
| Peak power | 80 TW | 120 TW |
| Repetition Rate | 20 Hz | 50 Hz |
| Contrast | 1:10-10 at 10 ps | 1:10-10 at 10 ps |
| Output laser beam RMS pointing stability | < 1 µrad | < 1 µrad |
| Beam size | 120mm diameter, round | 120mm diameter, round |
L2 Experimental programme:
Reference:
Jonathan Tyler Green, tyler.green@eli-beams.eu
