Fiber Optic Splitters: Choosing Between FBT and PLC Technologies for High-Performance Networks
In the era of 5G, FTTH (Fiber-to-the-Home), and hyperscale data centers, optical splitters are critical for enabling high-bandwidth, low-latency connectivity. This guide compares FBT (Fused Biconical Taper) and PLC (Planar Lightwave Circuit) splitters—two dominant technologies shaping modern passive optical networks (PON).
FBT splitters, a legacy solution in telecom networks, use fused fibers to split signals.
Fiber Stripping: Remove coatings from silica fibers and bundle them based on desired outputs (e.g., 1×2, 1×4).
Fusion & Tapering: Melt fibers at high heat, stretch them into a biconical shape, and twist to achieve the split ratio.
Packaging: House the fused area in steel tubes or ABS casings for protection.
| Pros | Cons |
|---|
| ✅ Low cost for small splits (1×2 to 1×8) | ❌ Limited to 850/1310/1550nm wavelengths |
| ✅ Custom split ratios (e.g., 70:30) | ❌ High failure rate (>1×8 splits) |
| ✅ Mature, simple production | ❌ Temperature sensitivity (-5°C to 75°C) |
| ❌ Bulkier size, poor uniformity |
PLC splitters leverage semiconductor waveguide chips for precise, high-density splitting.
Signal Input: Light enters via an input fiber array.
Waveguide Splitting: A silica chip divides signals evenly across outputs (1×8 to 1×64).
Output Coupling: Signals exit through output fibers.
| Pros | Cons |
|---|
| ✅ Broad wavelength (1260–1650nm) | ❌ Higher upfront cost for low splits |
| ✅ Compact size (ideal for FTTH OLTs) | ❌ Fixed split ratios (e.g., 50:50) |
| ✅ ±0.8 dB uniformity (Telcordia GR-1209) | ❌ Complex manufacturing |
| ✅ High reliability (MTBF >200k hours) |
|
FBT: Limited to 850/1310/1550nm (±40nm).
PLC: Full C+L band (1260–1650nm), ideal for DWDM and NG-PON2.
FBT: Custom ratios (e.g., 30:70) for asymmetric splits.
PLC: Fixed equal splits (e.g., 1×32 = 3.125% per port).
FBT: Rural FTTX, legacy RFoG, small LANs.
PLC: 5G fronthaul, cloud data centers, urban FTTH.
PLC splitters dominate GPON/XGS-PON architectures due to:
High Uniformity: ±0.8 dB loss ensures long-reach transmission (up to 60 km).
Scalability: 1×64 splits support dense user environments.
Future-Proofing: Compatible with 25G/50G-PON and coherent optics.
FTTH: Centralized splitters in OLT cabinets distribute signals to 64+ homes.
Data Centers: Spine-leaf architectures use PLCs for 400G breakout.
5G Fronthaul: Low-loss splits enable CRAN (Cloud RAN) connectivity.
While FBT splitters suit niche, low-cost applications, PLC technology delivers unmatched performance for high-speed, high-density networks. Key advantages include:
Wavelength Agility: Supports DWDM and multi-service aggregation.
Reliability: <0.5 dB loss fluctuation in extreme conditions.
ROI: Lower OPEX via reduced maintenance and upgrades.
For 5G-ready or hyperscale deployments, PLC splitters are the clear choice.
