Yep, actually, I think the micro links topped out at about 270 GHz. But you're right, we did some point to point telemetry using collimated IR systems. The really wild stuff was using ultrasonic signals at 530 Khz amplitude modulated at 250 yards.
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The ultimate result of shielding men from the effects of folly is to fill the world with fools.
-- Herbert Spencer, English Philosopher (1820-1903)