Bonfires and heliographs shared other limitations. They were slow, unusable in bad weather and labour-intensive. Multiple observers, all within sight of each other, had to take down the message and repeat it along the chain. But the idea of using light for communication was never entirely shelved. Today, hobbyist can construct a modern photophone now known as a light beam transceiver.
TAB books have plans and circuit diagrams for constructing a transceiver.
One can use a searchlight beam or laser as the light carrier. Most light beam communication today makes use of fiber optics which is dependent on fiber-optic cable connections between the sender and receiver. If you are not adept with electronic instruments, then you can always attempt telepathy. After all, it is the most cost-effective means of communication even if not as reliable as electronic and mechanical means. Telepathy has been tested in the scientific laboratory and results have varied from test to test.