Laser-sustained plasma (LSP) source featuring high brightness and broadband spectral coverage is found to be powerful in various fields of scientific and industrial applications. However, the fundamental limit of low conversion efficiency constrains the system compactness and widespread applications of such broadband light sources. In this paper, we propose an innovative orthogonal LSP to break through the conversion efficiency limitation. Driven by the elevated conversion efficiency from absorbed laser power to ultraviolet (UV) emission, a compact broadband source (250–1650 nm) with UV spectral radiance exceeding 210 \({mW}/({{mm}}^{2}\,\cdot\, {sr}\,\cdot\, {nm})\) is achieved with >100 W pump laser. With the plot of a two-dimensional refractive index model, we report an important conceptual advance that the orthogonal design eliminates the influence of the negative lensing effect on laser power density. Experimental results unambiguously demonstrate that we achieve a bright compact UV-VIS-NIR source with negligible thermal loss and the highest conversion efficiency to our knowledge. Significant enhancement of 4 dB contrast-to-noise ratio (CNR) in spectral single-pixel imaging has been demonstrated using the proposed ultrabroadband source. By establishing the quantitative link between pumping optics design and plasma absorption, this work presents a compact broadband source that combines superior conversion efficiency and unprecedented brightness, which is essential to high-speed inspection and spectroscopy applications.

激光维持等离子体 (LSP) 源具有高亮度和宽带光谱覆盖范围，在科学和工业应用的各个领域中都具有强大的功能。然而，低转换效率的根本限制限制了此类宽带光源的系统紧凑性和广泛应用。在本文中，我们提出了一种创新的正交LSP来突破转换效率限制。在从吸收的激光功率到紫外 (UV) 发射的转换效率提高的推动下，紧凑型宽带光源 (250–1650 nm) 的紫外光谱辐射亮度超过 210 \({mW}/({{mm}}^{2}\ ,\cdot\, {sr}\,\cdot\, {nm})\)是使用 >100 W 泵浦激光器实现的。通过二维折射率模型图，我们报告了一个重要的概念进展，即正交设计消除了负透镜效应对激光功率密度的影响。实验结果明确表明，我们实现了明亮紧凑的紫外-可见-近红外光源，其热损失可以忽略不计，并且据我们所知具有最高的转换效率。使用所提出的超宽带源已证明光谱单像素成像的对比度噪声比 (CNR) 显着增强 4 dB。通过建立泵浦光学设计和等离子体吸收之间的定量联系，这项工作提出了一种紧凑的宽带源，它结合了卓越的转换效率和前所未有的亮度，这对于高速检测和光谱应用至关重要。