Micro-optics couplers use individual optical elements such as prisms, lens, mirrors, etc. These elements divide the input optical signal into two or more separated light beams. Optical fiber couplers generally have the following characteristics: First, the device is composed of optical fiber, which is an all-fiber device; second, the demultiplexing and. The construction of couplers and branches, including the associated losses, is described, including the use of planar waveguide structures. Types of couplers (stirring surface couplers and surface couplers) are described. It's primarily employed to combine and split signals in optical networks, and it's also referred to as a directional coupler. This capability is fundamental.