Cables and Connectors
As mentioned, Thunderbolt 1 and 2 use a mini DisplayPort (mini DP) connector. In Figure 3, you can see a Thunderbolt 1 port on a motherboard.
There are two types of cables for Thunderbolt 1 and 2: electrical or optical. Electrical cables can be anywhere between 4 inches and 9.8 feet (10 cm to 3 m) long, while optical cables can be between 32.8 feet and 65.6 feet (10 m to 20 m) long. The use of one kind of cable or the other will depend on the cable length you want.
One advantage of the Thunderbolt 1 and 2 connections is that both electrical and optical cables use the same connector type, the mini DisplayPort (mini DP). This is an electrical connector, so optical cables have circuitry at both ends to convert electrical signals into optical signals and vice versa. This circuit is available inside the rectangular box where the connector is attached. See Figure 6. Because of that, optical cables will not be inexpensive.