Wang Ruipeng, Sun Yuqi, Wang Xinyu, Zheng Zhongming, Chi Zhendong, Li Wenhao, Jiang Yanxiu
Opt Express. 2025 Mar 10;33(5):9604-9618. doi: 10.1364/OE.547670.
Grazing incidence gratings (GIGs) are diffractive optical components used in pulsed narrowband tunable lasers. To narrow the output linewidths of external-cavity semiconductor lasers further, a metal-dielectric GIG with high diffraction efficiency and high groove density was designed and fabricated. The grating was optimized using a combination of the Fourier modal method and the particle swarm optimization algorithm. When transverse-magnetically-polarized light at a wavelength of 650 nm was incident at a grazing angle of 89°, the theoretical diffraction efficiency of the -1st order light reached 68%, which is three times higher than that of traditional gratings. A rectangular grating with a groove density of 2800 gr/mm was fabricated using holographic exposure and scanned reactive ion beam etching techniques, and its diffraction efficiency was measured. The experimental results confirmed the excellent performance of the metal-dielectric GIG, indicating its potential for applications, including narrow-linewidth lasers, optical communications, and spectral analysis.
掠入射光栅（GIG）是用于脉冲窄带可调谐激光器的衍射光学元件。为了进一步缩小外腔半导体激光器的输出线宽，设计并制作了一种具有高衍射效率和高槽密度的金属 - 介质GIG。采用傅里叶模态法和粒子群优化算法相结合的方式对光栅进行了优化。当波长为650 nm的横向磁偏振光以89°的掠入射角入射时，-1级光的理论衍射效率达到68%，这比传统光栅高出三倍。利用全息曝光和扫描反应离子束蚀刻技术制作了槽密度为2800 gr/mm的矩形光栅，并测量了其衍射效率。实验结果证实了金属 - 介质GIG的优异性能，表明其在窄线宽激光器、光通信和光谱分析等应用中的潜力。
