Laser communication's promise — huge bandwidth, no spectrum license — comes with a curse: the beam is so tight you have to aim it with extraordinary precision. US11336371B2, granted to CACI, Inc.—Federal on May 17, 2022, claims a "defocuser for compact free space communication" that eases that burden.
The CPC is optical-comms specific: H04B 10/1127 and H04B 10/118 (free-space optical transmission), with G02B 27/0927 (optical elements for beam shaping). The defocuser is the beam-shaping element doing the work.
The mechanism is a deliberate, controlled defocus. A perfectly collimated laser link demands that two terminals — often on moving platforms hundreds or thousands of kilometers apart — hold alignment to microradians. By intentionally widening (defocusing) the beam, the system creates a larger "hit" area at the receiver, so small pointing errors no longer break the link. You sacrifice some received power and peak data rate, but you gain a system that actually closes the link with a compact, lighter pointing assembly.
Spectrum plus geometry is the battleground, and this is a pure geometry play: spend a little link margin to buy a lot of pointing tolerance. For a compact terminal — a small satellite, a drone, a man-portable unit — that trade can be the difference between feasible and not.
The honest caveat: defocusing to ease acquisition and tracking is a known optical technique, so the claim covers CACI's specific compact implementation, not the idea broadly. But it is a clean illustration of the real engineering frontier in laser comms — not raw data rate, which the physics already grants, but making the terminal small, robust, and easy enough to aim that it can be fielded at scale.