  We demonstrate a hybrid laser microfabrication approach, which combines the
technical merits of ultrafast laser-assisted chemical etching and carbon
dioxide laser-induced in-situ melting, for centimeter-scale and bonding-free
fabrication of 3D complex hollow microstructures in fused silica glass. With
the developed approach, large-scale fused silica microfluidic chips with
integrated 3D cascaded micromixing units can be reliably manufactured.
High-performance on-chip mixing and continuous-flow photochemical synthesis
under UV LEDs irradiation at ~280 nm were demonstrated using the manufactured
chip, indicating a powerful capability for versatile fabrication of highly
transparent all-glass microfluidic reactors for on-chip photochemical
synthesis.
