The inertial sensor is the heart of all navigation systems which is capable o
f detecting movement and rotation in three directions. This sensor can be
widely used in space (cube) satellites, drones, underwater vehicles, defens
e industry, robotics, autonomous vehicles and submarines, etc. Fiber optic
gyroscope (FOG) is the core technology in an inertial sensor and is regulat
ed by the US International Traffic in Arms Regulations (ITAR). It is not easy
to purchase FOGs from abroad. In recent years, major foreign government
s and private companies have dedicated in the development of miniaturiz
ed FOGs using photonic integration technology. With the rapid evolution
of semiconductor CMOS manufacturing process, the research of silicon ph
otonics technology has attracted wide attention. We began silicon photon

ics research with TSMC since 2016 to explore the possibilities in silicon ph
otonics. We started our journey in the development of silicon photonics b
ased fiber optics gyroscopes (SiPho-FOGs) since 2018 and realized the wo
rld’s first tactical-grade miniaturized SiPho-FOG in 2022. These results h
ave attracted the attention of domestic and foreign media and related ind
ustry, government and academia.
A high-precision inertial sensing device usually requires three-axis FOGs t
o provide rotation information in three directions. A common method is t
o assemble three single-axis FOGs, which are costly and bulky. We continu
ed to work toward the miniaturization of three-axis FOGs by using wavele
ngth division multiplexing approach and had achieved key technology opt
imizations. All the efforts and concepts had been protected by the ROC an
d US patents, and was reported in the top international journal in this fiel
d. This research project is supported by National Science and Technology
Council, Taiwan and by the Ministry of National Defense.