We implement a multi-color laser engine with silicon nitride photonic integrated circuit technology, that combines four fluorophore excitation wavelengths (405 nm, 488 nm, 561 nm, 640 nm) and splits them with variable attenuation among two output fibers used for different microscope imaging modalities. With the help of photonic integrated circuit technology, the volume of the multi-color laser engine’s optics is reduced by two orders of magnitude compared to its commercially available discrete optics counterpart. Light multiplexing is implemented by means of a directional coupler based device and variable optical attenuation as well as fiber switching with thermally actuated Mach-Zehnder interferometers. Total insertion losses from lasers to output fibers are in the order of 6 dB at 488 nm, 561 nm, and 640 nm. Higher insertion losses at 405 nm can be further improved on. In addition to the system level results, spectrally resolved performance has been characterized for each of the developed devices.

中文翻译：

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用于生命科学应用的基于氮化硅PIC的多色激光引擎

我们采用氮化硅光子集成电路技术实现了一种多色激光引擎，该引擎结合了四个荧光团激发波长（405 nm，488 nm，561 nm，640 nm），并以可变衰减的方式将它们分成两个用于不同显微镜成像的输出光纤。方式。借助光子集成电路技术，与市售的分立光学器件相比，多色激光引擎的光学器件的体积减少了两个数量级。光复用是通过基于定向耦合器的设备和可变的光衰减以及通过热驱动的Mach-Zehnder干涉仪进行的光纤切换来实现的。从激光器到输出光纤的总插入损耗在488 nm，561 nm和640 nm处约为6 dB。可以进一步改善405 nm处的较高插入损耗。除系统级结果外，还对每个开发的设备进行了频谱分辨性能的表征。