Development of a Stimulated Brillouin Scattering Phase Conjugate Mirror for High Average Power Laser
Abstract
The purpose of this research is to develop an SBS-PCM for high input average power more than 100 W. To achieve this goal, the researchers tried to find the proper SBS media for high input average power. The researchers have tested several kinds of liquids (HT110 and HT270), solid (metallic inclusion free fused silica), and gas (highly pressurized N2 gas) media to make an SBS cell. For the liquids, the researchers used purified HT110 and purified HT270. The researchers measured the SBS reflectivity and the SBS reflected beam patterns of HT110 and HT270 by using Kumgang laser operating at 1 kHz repetition rate. The SBS reflectivity of HT110 and HT270 at the input energy of 50 mJ@1kHz were 64% and 43%, respectively. The SBS reflected beam patterns of HT270 were better than those of HT110, because of the high boiling point and high viscosity of HT270. However, the SBS reflected beam patterns of HT270 were still unstable because of convection even without boiling.For the solid, the researchers used metallic inclusion free fused silica (Suprasil 311 made by Heraeus). The authors measured the SBS reflectivity and SBS reflected beam patterns of Suprasil 311 by using Kumgang laser operating at 1 kHz repetition rate. The SBS reflectivity at the input energy of 50 mJ@1kHz (input laser beam intensity 25 GW/cm2) was 35%. The SBS reflected beam patterns were stable and good, but OBD was observed at the input energy of 35mJ@10Hz (input laser beam intensity 53 GW/cm2), while the OBD threshold of Suprasil 311 is known as 55 GW/cm2.For the gas, the researchers tested highly pressurized N2 gas. The authors measured the SBS reflectivity and SBS reflected beam patterns using Spectra-physics laser(GCR-100) operating at 10 Hz. The SBS reflectivity at the input energy of 240 mJ (363 GW/cm2) and the N2 pressure of 100 bar was 67%. Up to 50 bar of the N2pressure, the OBD occurred severely. The higher the N2 pressure is, the lower the OBD occurrence probability is. However, the OBD still
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 26, 2023
- Accession Number
- AD1204575
Entities
People
- Hong Jin Kong
Organizations
- KAIST