Interferometers usually require long paths for the ever-increasing requirements of high-performance operation, which hinders the miniaturization and integration of photonic circuits into very compact devices. Slow-light based interferometers provide interesting advantages in terms of both compactness and sensitivity, although their optimization is computationally costly and inefficient, due to the large number of parameters to be simultaneously designed. Here we propose the design of slow-light-enhanced bimodal interferometers by using principal component analysis to reduce the high-dimensional design space. A low-dimensional hyperplane containing all optimized designs is provided and investigated for changes in the silicon core and cladding refractive index. As a result, all-dielectric single-channel interferometers as modulators of only 33 µm2 footprint and sensors with 19.2 × 103 2πrad/RIU·cm sensitivity values are reported and validated by 2 different simulation methods. This work allows the design and optimization of slow light interferometers for different applications by considering several performance criteria, which can be extended to other photonic structures.