Steinle Tobias, Kumar Vikas, Floess Moritz, Steinmann Andy, Marangoni Marco, Koch Claudia, Wege Christina, Cerullo Giulio, Giessen Harald
4th Physics Institute and Research Center SCoPE, University of Stuttgart, D-70569, Stuttgart, Germany.
IFN-CNR, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133, Milan, Italy.
Light Sci Appl. 2016 Oct 7;5(10):e16149. doi: 10.1038/lsa.2016.149. eCollection 2016 Oct.
We introduce an extremely simple and highly stable system for stimulated Raman scattering (SRS) microscopy. An 8-W, 450-fs Yb:KGW bulk oscillator with 41 MHz repetition rate pumps an optical parametric amplifier, which is seeded by a cw tunable external cavity diode laser. The output radiation is frequency doubled in a long PPLN crystal and generates 1.5-ps long narrowband pump pulses that are tunable between 760 and 820 nm with >50 mW average power. Part of the oscillator output is sent through an etalon and creates Stokes pulses with 100 mW average power and 1.7 ps duration. We demonstrate SRS microscopy at a 30-μs pixel dwell time with high chemical contrast, signal-to-noise ratio in excess of 45 and no need for balanced detection, thanks to the favorable noise properties of the bulk solid-state system. Cw seeding intrinsically ensures low spectral drift. We discuss its application to chemical contrast microscopy of freshly prepared plant tissue sections at different vibrational bands.
我们介绍了一种用于受激拉曼散射（SRS）显微镜的极其简单且高度稳定的系统。一台8瓦、450飞秒、重复频率为41兆赫的Yb:KGW体振荡器泵浦一个光学参量放大器，该放大器由一个连续波可调谐外腔二极管激光器注入种子光。输出辐射在一块长周期极化铌酸锂（PPLN）晶体中进行倍频，产生1.5皮秒长的窄带泵浦脉冲，其平均功率大于50毫瓦，波长在760至820纳米之间可调。振荡器输出的一部分通过一个标准具，产生平均功率为100毫瓦、持续时间为1.7皮秒的斯托克斯脉冲。由于体固态系统具有良好的噪声特性，我们展示了在30微秒像素驻留时间下的SRS显微镜，具有高化学对比度、信噪比超过45且无需平衡检测。连续波注入本质上确保了低光谱漂移。我们讨论了其在不同振动波段对新鲜制备的植物组织切片进行化学对比度显微镜检查中的应用。
