What's the difference between PLC and FBT

At present, the main optical divider are planar optical waveguide and fused taper technology two kinds.A brief introduction of the technology of the following two kinds of products.

(1) planar waveguide optical divider (PLC Splitter).

This device inside divider consists of a light at the ends of the chip and fiber array of coupling.Chips make grow in the quartz substrate using semiconductor process, a layer of light waveguide chip is an input terminal and N output waveguide. Then on both ends of the chip, respectively, input and output optical fiber array seal shell, form a with one input and output N fiber optical divider. According to user needs, can input and output for naked fiber optic components, in all kinds of packaging boxes, input and output optical fiber with pine casing protection, and can be an external connector.

Due to the semiconductor technology, the technology process, consistency, good stability, not related, loss and the wavelength channel good uniformity, compact structure small volume, large-scale industrialization of mature technology, has been most countries such as Japan, the United States, South Korea, France specified using the technology. The light of the commonly used divider with x N 1 and 2 xn (N - 4, 8, 16, 32, 64).

(2) fused taper fiber divider (FBT Splitter)

Fused taper technology is will be bound together two or more optical fibers, and then pull the cone machine melt stretching, stretching process to monitor various optical fiber coupling ratio, spectral ratio requirements after molten stretching, one side retain a single fiber (the rest of the cut) as input, the other side is a multiplexed output end..

A cone technology is tied together, will be more optical fibers in a special cone on the melt at the same time, stretching, and real-time monitoring of various optical fiber loss. At present, the mature of a cone process has can be below 1 x 4 devices at a time. Lab has a record of 1 x 8, but batch production process is not yet mature.

Currently overseas FTTH projects, low grade road optical divider (below 1 x4) often USES a cone technology devices.

Concatenated pyrometric cone type 1 xn shunt devices are made of 1 x 2 (N - 1) pull the cone cell series welding a packaging box (figure IC for schematic diagram, figure 4 b to 1 x 8 packaging box physical picture). byBetween unit fiber need to weld, and need to have minimum bending radius, usually volume is larger, such as: 1 x 8 optical divider by seven 1 x 2 unit welding and become, package size is 100 * 80 x9mm usually.

And compare the performance of two kinds of device

1.the working wavelength

Planar waveguide optical divider is not sensitive to wavelengths, which means different wavelengths of light its insertion loss is very close, usually work up to 1260-1650 nm wavelength, covers the present various PON standards required for all possible using the wavelength of the wave and various test equipment needed.

Pull a tapered optical divider, the optical fiber mode field generated in the cone drawing process of change, need to work according to the need to adjust the process monitoring window, according to the need to work can be adjusted to 1310 nm wavelength, the 1490 nm, 1550 nm working wavelength (commonly known as the working window). Usually single window and double window component process control is relatively mature, three window process is relatively complex. Under the condition of process control is bad, with the unceasing change of working time and temperature, insertion loss will change.

2. light uniformity

Ratio of planar waveguide devices determined by design mask version. At present commonly used devices spectroscopic, than is uniform. Because of the high consistency of semiconductor technology, the uniformity of the device channel is very good. Can guarantee the size of the output light good consistency.