Using the encoding as implemented in this paper, it is theoretically possible to send 4 bits per photon. Using higher-order orbital angular momentum light sources would probably increase that further.

NHK is advancing encoding standardization at MPEG to record and transmit natural 3D video. At present, we are studying encoding schemes using data formats of the encoding target and depth information.

The synchronous support often uses encoding schemes like 4B/5B and 8B/10B. The 4B/5B uses 5 bits to encode 16 (4-bit) symbols that are unique enough that clock recovery/synchronization is possible ...

To answer your question, I reached out to Steve Halliday, the president of consulting firm High Tech Aid, who is an expert on RFID standards and the encoding schemes they use. Here is Steve’s reply: ...