What Is an Optical Splitter?

An optical splitter, also known as a fiber optic splitter or beam splitter, is a passive device used in fiber optic networks to divide or split an incoming optical signal into multiple output signals. It plays a crucial role in distributing optical signals efficiently and reliably to multiple destinations, such as different network devices or subscribers.

The primary function of an optical splitter is to split the light power from an input fiber optic cable into multiple output fibers, each carrying a portion of the original signal. This splitting process is achieved through a combination of optical components and techniques, allowing for the simultaneous transmission of the same signal to multiple endpoints without significant loss or degradation.

Optical splitters are commonly used in various applications, including telecommunications, cable television (CATV) networks, passive optical networks (PONs), and fiber-to-the-home (FTTH) installations. They provide a cost-effective and scalable solution for expanding network capacity and connecting multiple users or devices to a single optical fiber.

There are different types of optical splitters available, each with its own characteristics and areas of application. The most common types include:

Fused Biconical Taper (FBT) Splitters: FBT splitters are constructed by fusing and tapering together two or more fibers, resulting in a compact device. They are cost-effective and widely used in various applications. FBT splitters can split the light signal unevenly, with different splitting ratios, such as 50:50, 70:30, or 80:20.

Planar Lightwave Circuit (PLC) Splitters: PLC splitters utilize a waveguide chip to divide the optical signal. The chip is fabricated using lithographic techniques and provides excellent splitting performance with uniform splitting ratios. PLC splitters can split the signal evenly, such as 1x2, 1x4, 1x8, or unevenly with custom ratios.

The operating principle of an optical splitter involves several key components and processes:

Input Fiber: The incoming optical signal, usually transmitted through a single-mode fiber, is connected to the input port of the splitter.

Splitting Region: This region consists of the necessary optical components, such as waveguides or fused fibers, that divide the input signal into multiple output signals.

Output Fibers: The divided signals are directed to the output ports of the splitter, where each output fiber carries a portion of the original signal.

Splitting Ratio: The splitting ratio determines how the input signal is divided among the output fibers. It can be pre-determined during the manufacturing process or customized based on specific requirements.

When an optical signal enters the splitter, it undergoes a process called power splitting. The splitting ratio determines the power distribution among the output fibers. For example, in a 1x2 splitter with a 50:50 splitting ratio, the input power is divided equally between the two output fibers.

It is important to note that optical splitters are passive devices, meaning they do not require any external power source or active electronic components. This passive nature ensures reliable and maintenance-free operation, making optical splitters suitable for long-term deployments in various network environments.

The performance of an optical splitter is influenced by several factors, including splitting ratio, insertion loss, uniformity, and directivity:

Splitting Ratio: The splitting ratio determines how the input signal power is divided among the output fibers. It is expressed as a ratio, such as 50:50 or 70:30, indicating the proportion of power allocated to each output.

Insertion Loss: Insertion loss refers to the amount of power lost during the splitting process. It is crucial to minimize insertion loss to maintain signal strength and ensure efficient transmission to the output fibers.