FBT Splitter | Fused Biconic Taper Fiber Optic Splitter for PON Networks

Introduction

Opelink manufactures high-quality FBT (Fused Biconic Taper) splitters, providing cost-effective solutions for optical signal splitting in fiber optic networks. With over 13 years of experience in optical passive components, we serve customers in more than 50 countries with reliable, Telcordia-compliant products.

FBT splitters are created by fusing and tapering two optical fibers together, allowing optical power to be split between output ports based on precise coupling ratios. This mature technology offers excellent performance for low-port-count applications, making it ideal for CATV systems, fiber optic sensors, and PON networks where cost efficiency is paramount.

Our FBT splitters are available in 1x2, 1x4, 1x8, and 2xN configurations, with customizable coupling ratios from 50/50 to 1/99. We offer single-mode and multimode options, with standard, wideband, and dual-window variants to meet diverse wavelength requirements.

What is an FBT Splitter?

An FBT (Fused Biconic Taper) splitter, also known as a fused coupler, is a passive optical device that splits optical power between two fibers through a fused region created by heating and pulling two fibers together.

The manufacturing process involves:
1. Removing the coating from two optical fibers
2. Twisting the bare fibers together
3. Heating the junction with a flame or electric arc
4. Pulling the fibers to create a tapered fused region
5. Monitoring the coupling ratio during the pulling process
6. Encapsulating the fused region for protection

This process creates a precise coupling ratio that determines how optical power is distributed between the output ports. FBT splitters can be cascaded in tree configurations to create 1xN or 2xN splitters with multiple outputs.

FBT Splitter Types

Opelink offers three types of FBT splitters to meet different application requirements:
1. Standard Type FBT Splitter
Optimized for single-wavelength applications at 1310nm or 1550nm. Features low excess loss (typically <0.1dB) and excellent long-term stability. Available with polarization-independent performance for applications where PDL must be minimized.
2. Wideband Type FBT Splitter
Designed for WDM applications covering 1260-1620nm wavelength range. Maintains consistent coupling ratios across the entire bandwidth, making them ideal for CWDM systems and broadband applications.
3. Dual-Window Type FBT Splitter
Optimized for simultaneous operation at 1310nm and 1550nm, the two primary wavelengths used in telecom networks. Provides balanced performance at both wavelengths with minimal variation in coupling ratio.

Technical Specifications

Parameter	Specification
Operating Wavelength	1310nm & 1550nm (Dual Window)
Coupling Ratio Range	50/50 to 1/99 (Customizable)
Excess Loss	≤0.1dB (1x2), ≤0.2dB (1x4), ≤0.4dB (1x8)
PDL	≤0.1dB (50/50 ratio)
Return Loss	≥55dB
Directivity	≥55dB
Operating Temperature	-40°C to +85°C
Storage Temperature	-40°C to +85°C
Fiber Type	SMF-28e, G.657A, or Custom
Package Options	250μm bare fiber, 900μm loose tube, 3mm cable

Applications

• CATV Distribution: RF-over-fiber signal splitting for cable television networks
• Fiber Optic Sensors: Signal distribution in sensing and monitoring applications
• Test Equipment: Power tapping for network monitoring and testing
• PON Networks: Cost-effective splitting in FTTH deployments (low port counts)
• Telecommunications: Duplex transmission on single fiber
• WDM Systems: Wideband couplers for wavelength division multiplexing

FAQ

Q1: What is the difference between FBT and PLC splitters?

A: FBT splitters use fused fiber technology, offering cost-effective solutions for low port counts (1x2, 1x4) with customizable coupling ratios. PLC splitters use planar waveguide technology, providing better uniformity and lower loss for high port counts (1x16, 1x32, 1x64). FBT is ideal for cost-sensitive, low-port applications; PLC is preferred for high-port PON networks.

Q2: Can I get custom coupling ratios for FBT splitters?

A: Yes, Opelink offers custom coupling ratios from 50/50 to 1/99 in 1% increments. Common ratios include 50/50, 40/60, 30/70, 20/80, 10/90, 5/95, and 1/99. Custom ratios require minimum order quantities and may have longer lead times.

Q3: What fiber types are available for FBT splitters?

A: We offer standard single-mode fiber (SMF-28e, G.652D), bend-insensitive fiber (G.657A1, G.657A2), and multimode fiber (OM1, OM2, OM3, OM4). Custom fiber types can be accommodated upon request.

Q4: Are FBT splitters suitable for outdoor applications?

A: Yes, when properly packaged. Opelink offers FBT splitters in steel tube packages suitable for outdoor splice closures and distribution boxes. The steel tube provides mechanical protection and moisture resistance for harsh environment deployments.

Q5: What is the typical lead time for FBT splitter orders?

A: Standard products with common configurations (1x2, 1x4 with standard ratios) typically ship within 3-5 business days. Custom products may require 2-3 weeks depending on quantity and specifications. Large volume orders should be scheduled in advance.