To address the NASA Earth Science Division need for high-speed fiber optic multiplexers for next generation lidar systems, Luminit proposes to develop a new Fiber Optic Micromultiplexer (FOMM) based on InP/InGaAsP photonic integrated circuits (PIC) and digital optical switches (DOS). This approach makes innovative use of a modular expandable binary tree architecture for robust high-speed switching with a new application of the latest PIC and DOS technology. This approach enables us to design a lightweight (200 g), compact multiplexer that consumes only 1 A of electricity and can switch a fiber-coupled NIR laser transmitter among 16 single-mode fiber outputs in 4 ns while consuming only 5 W of electricity. In Phase I, Luminit will demonstrate the feasibility of ~20 ns switching and ~1 W laser power with a proof-of-principle 1-to-4 FOMM that has three electro-optical fiber switches, which will reduce the development risk of a Phase II 1-to-16 prototype that incorporates the PIC/DOS technology. The demonstrated results will offer NASA enhanced return signal and image resolution for lidar systems.