sam.gov
This certainly makes it sound like they are done throwing money at HRL to get useful miniature precision clocks. HRL got a number of contracts from about 2016 to 2023 to pull this off and insisted they could reinvent quartz timing to make it suitable for the military's purposes. I suggested that we instead build atomic clocks which work by using LASER bolometers to measure subtle changes in temperature which result from the same chance alignments of electrons in electron clouds of stable isotopes of heavy elements rather than using unstable isotopes.
The basic phenomenon that makes atomic timing possible are predictable decay events which are, despite popular belief, actually driven by enhanced Coulomb attraction between aligned electrons (these chance alignments work much like a clock) and protons. With a sufficient number of aligned electrons, protons can be "plucked" from a nucleus. When a proton is pulled away, a cesium neutron is energetically liberated. Atomic clocks (conventional ones) work by measuring neutron strikes resulting from this clockwork-like phenomenon.
I pointed out in 2022 that if these alignments happen in cesium isotopes, they would happen in any atom regardless of whether they were stable or not. I suggested that perhaps we could build clocks which work not on the basis of measurement of neutron emission, but rather on the measurement of temperature changes that result from the sudden tugging of a Coulomb Force Line projected by chance alignments of electrons. As bolometers can be made to be energy efficient and compact, this approach to precision timekeeping is much more logical than prior approaches. Elements such as lead could be used and the compact nature of the approach would permit large-scale parallelization to average multiple individual clocks for a net timekeeping apparatus that is far more accurate than any clock depending upon neutron decay detection.
Now, DARPA is suddenly talking about something it terms "Optical-Atomic" clocks. Pretty big coincidence, right? It is slightly disturbing that this was posted online two years ago and they are just getting around to prototyping and that 220 program managers with P.hD.s and thousands of subordinate undergrads couldn't come up with this.
Maybe if anyone knows a science and technology journalist they might be interested to do a story about this.