Power limits and a figure of merit for stimulated Brillouin scattering in the presence of third and fifth order loss.
Power limits and a figure of merit for stimulated Brillouin scattering in the presence of third and fifth order loss.
复制标题
DOI：
10.1364/oe.23.026628
复制
发表时间：
2015-08
期刊：
影响因子：
3.8
通讯作者：
Christian Wolff;Philipp Gutsche;M. J. Steel;B. Eggleton;C. Poulton
中科院分区：
文献类型：
--
作者：
Christian Wolff;Philipp Gutsche;M. J. Steel;B. Eggleton;C. Poulton
我们推导出一套设计准则和品质因数，以帮助强受激布里渊散射（SBS）的片上波导的工程过程。为此，我们研究了几种类型的损失的影响，可以通过SBS实现的斯托克斯波的总放大。我们考虑了三阶（双光子吸收，2PA）和五阶的线性损耗和非线性损耗，最明显的是2PA诱导的自由载流子吸收（FCA）。由此，我们推导出一个上限的连续波布里渊激光器的输出功率，并表明，任何给定的波导结构的最佳工作条件和最大可实现的斯托克斯放大由一个无量纲的参数ε涉及SBS增益和所有的损耗参数。我们提供了简单的表达式，最佳的泵浦功率，波导长度和可实现的放大，并在两个示例系统中展示其实用程序。值得注意的是，我们发现，2PA诱导的FCA是一个严重的限制SBS在硅和锗的波长分别短于2200 nm和3600 nm。相比之下，三光子吸收没有实际意义。
We derive a set of design guidelines and a figure of merit to aid the engineering process of on-chip waveguides for strong Stimulated Brillouin Scattering (SBS). To this end, we examine the impact of several types of loss on the total amplification of the Stokes wave that can be achieved via SBS. We account for linear loss and nonlinear loss of third order (two-photon absorption, 2PA) and fifth order, most notably 2PA-induced free carrier absorption (FCA). From this, we derive an upper bound for the output power of continuous-wave Brillouin-lasers and show that the optimal operating conditions and maximal realisable Stokes amplification of any given waveguide structure are determined by a dimensionless parameter ℱ involving the SBS-gain and all loss parameters. We provide simple expressions for optimal pump power, waveguide length and realisable amplification and demonstrate their utility in two example systems. Notably, we find that 2PA-induced FCA is a serious limitation to SBS in silicon and germanium for wavelengths shorter than 2200nm and 3600nm, respectively. In contrast, three-photon absorption is of no practical significance.