Counter-propagating lightwaves within a closed rotating loop enable rotation measurement as a result of the Sagnac effect [1]. And modern optical gyroscopes use long coiled optical fiber paths (fiber optic gyroscopes [2]) or resonant recirculation (ring laser gyroscopes [3]) to greatly enhance this effect. In recent years, the possibility of chip-based optical gyroscopes has garnered considerable attention. Such integrated optical gyrocopes could enjoy the advantages of integration and scalable manufacturing, and would offer rugged designs for operation in challenging environments [1]. Compact or chip-based ring laser gyroscopes [4–6], passive resonant gyroscopes [7–10], and interferometric gyroscopes [11] have been reported. Here we first review some of the enabling technologies of chip-integrated designs, overview recent results, and then focus on a chip-based laser gyroscope that has been used to measure the Earth’s rotation [6]. Key challenges and prospects for future improvements are also discussed.  

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