Hybrid Thin-Disk Amplifier
Sensors, Devices and Components
The patented hybrid technology overcomes this limitation exploiting the advantages of a thin-disk regenerative amplifier in combination with a multipass system. The system amplifies pulses within the cavity of the regenerative amplifier. Before accumulating destructive nonlinear phase distortions, a multipass system using the same active amplification volume as the regenerative amplifier boosts the pulse energy to a level inaccessible inside the regenerative amplifier. The absent electro-optical switch in the high-energy amplification process allows amplification without the need for CPA. Thus, this concept permits renouncing chirped pulse amplification leading to a compact setup including advantages in costs, stability and complexity of the system by abandoning stretcher and compressor units.
Figure 1 shows a schematic picture of the laser amplifier. The amplification process starts with a seed oscillator (red). Such laser oscillators deliver pulse energies from a few nanojoules (fiber oscillators) up to a few microjoules (thin-disk oscillators). An optical isolation stage and an optical switch couple the seed oscillator to the cavity of the regenerative amplifier. The Pockels cell then traps the pulses inside the resonator and the pulses remain in the resonator (figure 1, blue) until they reach energies of ~100μJ-1mJ. Once the pulses leave the regenerative amplifier, the optical isolator separates input and output beam paths and sends the pulses to the multipass amplifier (figure 1, green). Within several passes (2-40, depending on the needs) the remaining stored energy of the thin-disk is extracted boosting the pulse energy up to the multimillijoule level.
A prototype has successfully been tested showing amplification up to 6.5 mJ pulse energy at 5-10 kHz repetition rates within a simple multipass geometry incorporating up to 40 passes through the gain medium . These energy levels are competitive to standard systems based on CPA proving the validity of the concept and paving the way to compact powerful laser sources.
Granted patents EP 2873123 (validated in CH, CZE, DE, FR, GB, HU); US 9450367;
patent application in KR.
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- Ref.-No.: 1202-4510-WT (284.1 KiB)
PD Dr. Wolfgang Tröger
Phone: +49 89 / 29 09 19-27