Photonics
Not yet replacing GPUs. Photonic interconnect has arrived and is scaling fast. Photonic tensor cores are 24 to 36 months behind on a good trajectory.
Quantum
Not yet in full. Quantum clocks and gravimeters are already on submarines. A complete BEC-based IMU to replace GPS is 7 to 10 years out at minimum.
Astronomy
Metalenz, DARPA ENVision, HWO, PRIMA, T2SL detectors, ALD coatings, and China's germanium ban: nanophotonic IR optics for astronomy assessed in full.