Years after years, we have been following the development and advancement of fiber optics communication technologies. These advancements are made to meet the ever-accelerating demand for better, more efficient optical performances. Fiber optic splitter plays a significant role in optical networks by allowing signals on an optical fiber to be shared among two or more fibers. But what is a fiber optic splitter?
Fiber optic splitter, also known as optical splitter, or beam splitter, is an integrated waveguide optical power distribution device that can split an incident light beam into two or more light beams, and vice versa. The fiber optic splitter is one of the most important passive devices in the optical fiber link.
The fiber optic splitter device contains many input and output terminal, especially applied to a passive optical network (EPON, GPON, BPON, FTTH, FTTX etc.) to connect the main distribution frame (MDF) and the terminal equipment and to achieve the branching of optical signal.
Cassette Card Type PLC Splitter LGX Box
Types of Fiber Optic Splitter
Basically, there are two types of fiber splitter: Fused Biconical Taper splitter (FBT) and Planar Lightwave Circuit splitter (PLC).
Fused Biconical Taper Splitter (FBT)
The FBT splitter is the most common. FBT is the traditional technology in which two fibers are placed closely together, typically twisted around each other and fused together by applying heat. The fused fibers are protected by a glass substrate and then protected by a stainless steel tube. The quality of FBT fiber splitter has improved over time and they can be deployed in a cost-effective manner. FBT splitters are widely accepted and used in passive networks, especially for instances where the split configuration is smaller (1×2, 1×4, 2×2, etc.).
FBT Splitter
Planar Lightwave Circuit Splitter (PLC)
The PLC is a more recent technology, and offers a better solution for larger applications. PLC fiber splitters are used to separate or combine optical signals. A PLC is a micro-optical component based on planar lightwave circuit technology and provides a low cost light distribution solution with small form factor and high reliability. PLC splitters have high quality performance, such as low insertion loss, low PDL, high return loss and excellent uniformity over a wide wavelength range from 1260 nm to 1620 nm and have an operating temperature -40℃ to 85℃. When high split counts are needed and small package size and low insertion loss is critical, a PLC splitter is more ideal. Waveguides are fabricated using lithography onto a silica glass substrate, which allows for routing specific percentages of light. As a result, PLC splitters offer accurate and even splits with minimal loss in an efficient package.
Advantages and Disadvantages
The FBT splitter offers low cost, common materials (quartz substrate, stainless steel, fiber, hot dorm, GEL), and an adjustable splitting ratio. However, its losses are wavelength-dependent, it offers poor spectral uniformity, cannot ensure uniform spectroscopy, and is temperature sensitive.
PLC splitter: Losses are not sensitive to the wavelength, spectral uniformity is higher, it is more compact and is lower cost with greater degrees of splitting. However, device fabrication process is more complex.
Since both of them have their own advantages and disadvantages, users can rationally choose different types of optical splitters depending on the occasion and demands.
How Does Fiber Optic Splitter Work?
In Generally, when the light signal transmits in a single mode fiber, the light energy cannot be entirely concentrated in the fiber core. A small amount of energy will be spread through the cladding of the fiber. That is to say, if two fibers are close enough to each other, the transmitting light in an optical fiber can enter into another optical fiber. Therefore, the reallocation technique of optical signal can be achieved in multiple fibers, which is how fiber optic splitter comes into being.
Specifically speaking, the passive optical splitter can split, or separate, an incident light beam into several light beams at a certain ratio. As a simple example, how optical splitter with 1×4 split configurations can separate an incident light beam from a single input fiber cable into four light beams, transmit them through four individual output fiber cables. For instance, if the input fiber optic cable carries 1000 Mbps bandwidth, each user in the end of output fiber cables can use the network with 250 Mbps bandwidth.
The optical splitter with 2×64 split configurations is a little bit more complicated than the 1×4 split. As for the optical splitter with 2×64 split configurations, it is more complicated than the optical splitter with 1×4 split configurations. There are two input terminals and sixty-four output terminals in the optical splitter with 2×64 split configurations. Its function is to split two incident light beams from two individual input fiber cables into sixty-four light beams and transmit them through sixty-four light individual output fiber cables. With the rapid growth of FTTx worldwide, the requirement for larger split configurations in networks has increased to serve mass subscribers.
Split Ratio
A split ratio is the amount of light that is redirected from the network to the monitor ports on a passive optical network TAP. To determine the correct split ratio, a loss (power) budget should be calculated (more on that later). A 50/50 split ratio would indicate that 50% of the light budget coming into the TAP from the network is passed along to the end device, and 50% of the light budget is diverted to the monitoring device.
To understand how this goes as you change the ratio, for a 70/30 split ratio, 70% of the light budget is passed along to the end device and only 30% of the light budget is passed along to the network monitoring device.
The Importance of Fiber Optic Splitter
Optical splitters play an important role in FTTH PON networks where a single optical input is split into multiple outputs, thus allowing a single PON interface to be shared among many subscribers. The optical splitters have no active electronics and don’t require any power to operate. They are typically installed in each optical network between the PON OLT (optical line terminal) and ONTs (optical network terminals) that the OLT serves.
To sum up, fiber optic splitter provides a solution for improving the efficiency of optical infrastructures. PLC splitter and FBT splitter are varied in different aspects, hence choosing the right type of splitter for your network is also important.