| Autor: |
Kazuki Kawai, Yoshio Mizuta, Y. Hatano, Yuki Muramatsu, T. Sekine, Yasuki Takeuchi, Koichi Iyama, T. Kurita, Yoshinori Tamaoki, Takuto Iguchi, Shigeki Tokita, Yoshinori Kato, Takaaki Morita, J. Kawanaka, Yuki Kabeya, Masateru Kurata |
| Rok vydání: |
2019 |
| Předmět: |
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| Zdroj: |
Solid State Lasers XXVIII: Technology and Devices. |
| Popis: |
A 11.5 J at 40 ns output has been obtained from a diode-pumped cryo-cooled Yb:YAG ceramics active-mirror laser amplifier system. The system consists of two amplifier heads which has four Yb:YAG ceramic disks and two pump LD modules. The Yb:YAG ceramics are cooled by conventional cryostat from rear side and are pumped by LD modules from front-side. A pump pulse is delivered to Yb:YAG ceramics coaxially with a seed pulse to reduce damage risk at a dielectric coating of Yb:YAG ceramics due to simplified coating design. To realize this system design, a LD module has been developed to keep a rectangle pattern with side length of around 37 mm among imaging depth of about 10cm at working distance of about 410 mm. As an experimental result of two pass amplification, a 11.5 J pulse energy was obtained with input energy of 1.0 J and total pump energy of 90.2 J. Then, an optical-to-optical conversion efficiency was 11.6% and an extraction efficiency was estimated to be 42%. In our knowledge, this is the highest output energy with nano second pulse duration in cryo-cooled Yb:YAG active-mirror laser amplification scheme. A repetition rate of 0.05 Hz depends on a limitation of a repetition rate of the seed pulse. A dependence of small-signal-gain on pumping repetition rate of the active-mirror laser head was experimentally evaluated. From the experimental result, we have estimated a feasible repetition rate of over 5 Hz. A 10 Hz operation will be demonstrated to reduce a thermal resistance between Yb:YAG ceramics and cryostat. Finally, this laser amplifier system is installed to a 100-J class laser system as preamplifier. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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