(color online) Schematic of the 3D FsLMF system. The core components of the system are the femtosecond laser system and tightly focused high-numerical-aperture-(NA) lens (1.4, oil immersion). Two key controlling factors of the high fabrication precision are the stability of the pulse laser energy output and the scanning accuracy of the focus/sample. A charge-coupled-device (CCD) camera is used as the imaging system for optical modulation and monitoring. In the setup shown in the figure, other optical components are also included such as the polarization beam splitter (PBS), objective lens (OL), and piezoelectric transducer (PZT).^[1]