Some links you might find interesting: https://www.microsemi.com/products/timing-synchronization-systems/time-frequency-references/chip-scale-atomic-clock http

Some links you might find interesting: https://www.microsemi.com/products/timing-synchronization-systems/time-frequency-references/chip-scale-atomic-clock https://www.microsemi.com/products/timing-synchronization-sy... http://www.oewaves.com/media-events/item/50-oewaves-to-develop-an-all-optical-integrated-micro-primary-atomic-clock-ao-impac-for-darpa http://www.oewaves.com/media-events/item/50-oewaves-to-devel... http://www.gps.gov/governance/advisory/meetings/2016-05/lutwak.pdf http://www.gps.gov/governance/advisory/meetings/2016-05/lutw... https://www.darpa.mil/program/micro-technology-for-positioning-navigation-and-timing https://www.darpa.mil/program/micro-technology-for-positioni... I haven't seen much (haven't been looking either tho) since the Micro-PNT program which was in 2008. Sometimes that means that things are getting interesting, other times it's a dry hole. I'm interested in any later developments if you know of them.