We propose the development of a novel light (optical) gyro and accelerometer, light (weight), with unprecedented sensitivity. This project exploits the following innovations: The ability to generate two correlated frequency combs of the same repetition rate. Because of this correlation, while the bandwidth of a tooth of each comb is in the MHz range,the bandwidth of the interference is less than 1 Hz. Dispersion management boosting the sensitivity beyond our previous record of 0.01 microradian. Application to a dual comb ring laser leads to an ultrasensitive gyro without dead band. Application to a compact, stiff accelerometer which will have a displacement sensitivity of femtometers. We will implement of these ultrasensitive techniques in fiber lasers. With the resonant dispersive phase sensitivity enhancement seen with bulk component lasers, we expect to create a miniature device on par with the LIGO in terms of sensitivity. Potential NASA Applications (Limit 1500 characters, approximately 150 words) Lightweight expandable gyros and miniaturized accelerometers have application in commercial navigation. Because the fiber laser can be made of very large perimeter, it can have applications in monitoring the motion of tectonic plates. Furthermore, the ring laser gyro and linear accelerometer can be used in aerospace navigation, either stand-alone or as part of an Inertial Measurement Unit (IMU). With smaller weight, size, and power consumption, these instruments could even be used in small satellites. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words) Non-NASA applications in existing markets are the uses in aerial and naval navigation, especially if included in IMU's. Emerging market segments are for instance the LOON project of Google (to provide network access to remote regions), micro- and nano-satellites (SpaceX), commercial Space flight (Blue Origin, Virgin), or self driving cars.