The application of optical splitters is crucial in the deployment of FTTH networks

In FTTH (Fiber to the Home) network construction, optical splitters play a critical role. As passive components in the fiber optic link, the primary function of optical splitters is to split optical signals, enabling multiple users to share a single PON (Passive Optical Network) interface. Typically, optical splitters are installed between the Optical Line Terminal (OLT) and the Optical Network Terminal (ONT) within a PON system. This article will focus on how to utilize optical splitters for signal splitting in FTTH network construction, and will explore their implementation methods and design considerations.

1. Should You Choose a PLC Optical Splitter or an FBT Optical Splitter?

Before discussing the signal splitting construction of FTTH networks, it is essential to understand the different types of optical splitters. The two most commonly used optical splitters are PLC (Planar Lightwave Circuit) splitters and FBT (Fused Biconical Taper) splitters. Below are the main differences between them.

Parameters	PLC optical splitter	FBT optical splitter
Wavelength range	1260-1650 nm	Single/Dual/Triple Window
Split ratio	Even distribution	Even or uneven distribution
Volume	Small	Large volume when multi-path splitting
Wavelength sensitivity	Low	High
Price	Higher	Lower

With the widespread adoption of FTTH networks, PLC optical splitters have become a popular choice in FTTH applications due to their high splitting ratios and uniform signal distribution, effectively meeting the needs of more users.

2. Optical Splitting Deployment in FTTH Networks

PON (Passive Optical Network) is the core of FTTH networks, and optical splitters are essential components within the PON network. Common methods for optical splitting deployment in PON networks include primary splitting and secondary splitting.

Primary splitting involves concentrating optical splitters in a fiber distribution box, where a single fiber directly connects to the central office's OLT (Optical Line Terminal), while multiple fibers connect to several ONTs (Optical Network Terminals) at the user end. In primary splitting, the splitting ratio of the optical splitters is typically 1:32 or 1:64.

Secondary splitting refers to achieving signal splitting between the OLT (Optical Line Terminal) and the ONU (Optical Network Unit) through a cascade of two sets of optical splitters. This method includes two splitting points: the primary splitting point and the secondary splitting point.

The primary splitting point is usually located near the central office and typically uses a 1×4 optical splitter. The secondary splitting point is generally located closer to the user, such as in a hallway, and utilizes multiple optical splitters, often 1×8 splitters.

The primary splitting method (centralized arrangement of optical splitters) offers high flexibility, low operational costs, and ease of maintenance. In contrast, the secondary splitting method (cascaded arrangement of optical splitters) is characterized by a quicker return on investment and lower initial capital costs. Consequently, the primary splitting method is typically suited for densely populated urban or town areas, while the secondary splitting method is more appropriate for sparsely populated rural regions.

3. Designing Optical Splitting Ratios in FTTH Networks

In PON networks, commonly used optical splitters include 1:N（N=2~64）and 2:N（N=2~64） types, with "N" representing the number of output ports. Different splitting ratios of optical splitters serve various roles in FTTH networks.

Optical splitters are widely used in various aspects of FTTH network construction, including new residential developments, renovation of old neighborhoods, and rural broadband expansion. By utilizing optical splitters, comprehensive fiber-to-the-home coverage can be achieved, enhancing network transmission speed and stability to meet users' demands for high-quality connectivity.

In summary, optical splitters play an irreplaceable role in FTTH networks. Their advantages, including efficient signal splitting, cost reduction, simplified network structure, improved network reliability, and support for high-speed transmission, enable FTTH networks to deliver more convenient, efficient, and stable network services to users.