Laser brightness is a measure of the ability to deliver intense light to a target and encapsulates both the energy content and the beam quality. High-brightness lasers require that both parameters be maximized, yet standard laser cavities do not allow this. For example, multimode beams, a mix of many transverse modes, have a high energy content but low beam quality, while single transverse mode Gaussian beams have a good beam quality, but their small mode volume means a low energy extraction. Here we overcome this fundamental limitation and demonstrate an optimal approach to realizing high-brightness lasers. We employ intra-cavity beam shaping to produce a single transverse mode that changes profile inside the cavity, Gaussian at the output end and flattop at the gain end, such that both energy extraction and beam quality are simultaneously optimized. This work should have a significant influence on the design of future high-brightness laser cavities.

中文翻译：

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通过模式转换提高固态激光器的亮度

激光亮度是将强光传递到目标的能力的度量，并封装了能量含量和光束质量。高亮度激光器要求最大化两个参数，但是标准的激光腔不允许这样做。例如，多模光束是多个横向模的混合，具有较高的能量含量，但光束质量较低；而单横向模高斯光束具有良好的光束质量，但其小模体积意味着能量提取较低。在这里，我们克服了这一基本限制，并展示了一种实现高亮度激光器的最佳方法。我们采用腔内光束整形来产生一个单一的横向模式，该模式会改变腔内的轮廓，在输出端改变高斯分布，在增益端改变平坦度，这样就可以同时优化能量提取和光束质量。这项工作将对未来的高亮度激光腔的设计产生重大影响。