2X2 coupler introduction and application

Author：

Number of views：

Time：

2022-06-08

The 2x2 fused fiber coupler splits or mixes light between two fibers at a specified coupling ratio. ORTE offers customizable coupling ratios ranging from 01:99 to 50:50. The 2X2 fused tapered fiber coupler works in both directions, that is to say, all ports can be used as inputs. In the example diagram below, the optical input goes to port 1, and for our broadband coupler, port 3 and port 4 are the signal output and low power output respectively.

The terms "Throught Output-signal output" and "Tap Output-port with less output" refer to higher power output and lower power output respectively. For example, if light is input to the Port1 port of the coupler (1:99 coupling ratio), 99% of the transmitted light is coupled to the Port3 port on the other side of the coupler, and the remaining 1% is coupled to the Port4 port. In this example, the second Port3 port is called the signal output port, and the Port4 port is called the output-less port. For a 50:50 coupler, the signal output and the low power output have the same power output.

In our gray case couplers, the signal is always routed from Port1 to Port3, or Port2 to Port4, and the output-less path is always routed from Port1 to Port4, or Port2 to Port3 port.

Example 1 Splitting light from the signal output

For this example, a coupler is used to split light from a single input into the signal output and low power output ports, as shown in the figure below. In the table below, output ports are shown in blue.

Example 2 Mix two signals from two outputs

In this example, a coupler is used to mix the light of two inputs (indicated as signal 1 and signal 2). The output light is a mixed signal, which contains signal 1 and signal 2, and the ratio of the two depends on the coupling ratio. All ports are identified in the figure below. In the figure below, the input optical signal 1 and signal 2 are indicated in blue and green respectively, and the output port signal is shown in the figure below.