Dong Wu, Koji Sugioka, and co‐workers (see article number 1701299) create all‐glass optofluidic microchips consisting of built‐in microlenses with high robustness and optical performance by optimized single‐operation femtosecond laser assisted etching. A novel and simple tuning method is also developed via changing the liquid refractive indices while leaving the shape of the microlenses unchanged.
