They use phase detecting photodiodes and thermal effects to measure and tune a miniaturized ring gyro (single turn) to measure rotation in a MEMS device. Their

They use phase detecting photodiodes and thermal effects to measure and tune a miniaturized ring gyro (single turn) to measure rotation in a MEMS device. Their ratiometric compensation makes it much better than you might expect, but not (as is implied by the article above) better than larger gyros. The supplemental derivations and discussions/figures for this paper are available (in pdf) from the Caltech Library. https://authors.library.caltech.edu/88626/3/41566_2018_266_MOESM1_ESM.pdf https://authors.library.caltech.edu/88626/3/41566_2018_266_M... http://resolver.caltech.edu/CaltechAUTHORS:20180807-125405326 http://resolver.caltech.edu/CaltechAUTHORS:20180807-12540532.... - permalink Or the entire article ois available from Springer: https://www.nature.com/articles/s41566-018-0266-5 https://www.nature.com/articles/s41566-018-0266-5