Numerical analysis of the spatial behaviour of nanosecond optical parametric oscillators of beta-barium borate
Numerical analysis of the spatial behaviour of nanosecond optical parametric oscillators of beta-barium borate
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DOI：
10.1007/s003400050033
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发表时间：
2000-02
期刊：
影响因子：
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通讯作者：
R. Urschel;A. Borsutzky;R. Wallenstein
中科院分区：
文献类型：
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作者：
R. Urschel;A. Borsutzky;R. Wallenstein
对纳秒光学参量振荡器(OPOS)的时间和空间光束特性进行了数值分析。分析是对355 nm泵浦的临界位相匹配的β-硼酸钡OPO进行的。计算提供了OPO光束质量(由质量因子M2测量)与泵浦能量的关系的详细信息。一个重要的结果是，当泵浦能量超过阈值能量的1-2倍时，M2值显著增加。此外，对单个OPO脉冲的时间分析表明，在OPO振荡的最初几纳秒内，M2值强烈增加。通过考虑OPO信号光束和耗尽的泵浦辐射的空间轮廓的时间动力学，可以理解这种增加。
We report on a numerical analysis of the temporal and spatial beam properties of nanosecond optical parametric oscillators (OPOs). The analysis is performed for a 355-nm-pumped critically phase-matched OPO of beta-barium borate. The calculations provide detailed information on the dependence of the OPO beam quality (measured by the quality factorM2) on pump energy. An important result is the strong increase of theM2value for pump energies exceeding 1–2 times the energy at threshold. Furthermore, a temporal analysis of single OPO pulses indicates that theM2value strongly increases during the first few nanoseconds of the OPO oscillation. This increase is understood by considering the temporal dynamics of the spatial profiles of the OPO signal beam and the depleted pump radiation.