Fusion splicing is the bedrock of high-performance fiber optic networks, enabling seamless signal transmission through permanent, low-loss fiber joins. As a leading provider of fiber optic infrastructure, Weunion leverages cutting-edge tools like the AI9 and AI10 fusion splicers, paired with advanced OTDRs (NK3200/NK4000), to deliver precision splicing for applications spanning FTTH deployments, 5G backhaul, and data center interconnects. This guide dissects the fusion splicing process, toolchain optimization, and troubleshooting strategies to empower technicians and engineers
Fusion splicing fuses fiber ends via an electric arc, creating a molecular bond that mimics the fiber’s inherent strength. Key performance metrics include:
①Insertion Loss: ≤0.02 dB (SMF, AI10-rated) for long-haul networks.
②Return Loss: >60 dB (APC splicing) to suppress back reflections.
③Mechanical Integrity: >95% of the fiber’s tensile strength (tested per IEC 60793-1-40).
Unlike mechanical splicing, fusion eliminates air gaps, making it indispensable for high-bandwidth (≥100G) and long-distance (>100 km) networks.
Tool: Weunion WS-05 Precision Stripper
Design: Dual-blade system for 250μm/900μm buffers, adjustable tension to avoid microbends.
Technique:
①Align the fiber perpendicular to the stripper.
②Strip 30–40 mm of coating in a single, smooth motion.
③Inspect for nicks or uneven edges (magnification ≥100x).
Pro Tip: Clean stripper blades with isopropyl alcohol (IPA) pre-operation to prevent coating residue transfer.
Kit: Weunion CL-08 Fiber Cleaning Kit
Components: 99.9% anti-static IPA, laser-cut lint-free wipes, and a 12-slot reusable fiber holder.
Protocol:
①Soak a wipe with IPA; wipe the stripped fiber unidirectionally(from tip to buffer end).
②Repeat 2–3 times; inspect under 400x magnification (no dust, oil, or coating debris allowed).
Critical Note: Reusing wipes increases contamination risk, potentially adding 0.1–0.3 dB of splice loss.
Cleaver: Weunion CK12 Precision Cleaver
Specs: 0.2° angle tolerance, 50,000+ cut lifespan (diamond-coated blade with auto-rotation).
Steps:
①Position the cleaned fiber in the V-groove; set the cutting length (10–16 mm).
②Activate the cleaver; inspect the end-face (Figure 1) for:
③Smoothness (no chipping or microcracks).
④Perpendicularity (<0.5° deviation from the fiber axis).
Technical Impact: A flawed cut can increase insertion loss by 0.2–0.5 dB, detectable via OTDR testing.
Splicers: Weunion AI9 (Field Deployment) / AI10 (High-Volume)
AI9 Features: 5-second splice time, 3D active core alignment, 7800mAh battery (350+ splices per charge).
AI10 Features: AI-assisted splice optimization, auto-dust detection, 5-inch capacitive touchscreen.
Workflow:
①Load cleaved fibers into the splicer; activate auto-alignment (0.1μm precision).
②Select fiber type (SM/MM/APC); the splicer auto-tunes arc parameters:
SMF: 12–15 mA, 1200 ms arc duration.
MMF: 10–12 mA, 1000 ms arc duration.
①Verify X/Y-axis alignment (Figure 2) before initiating fusion.
Weunion Innovation: AI10’s “SmartSplice” mode auto-corrects alignment errors, reducing rework by 40%.
Heat-Shrink Sleeves: Weunion HS-06 (with stainless steel reinforcing rod)
Steps:
①Slide the sleeve over the splice, centering it on the joint.
②Cure in a Weunion HT-10 heater at 180°C for 60 seconds.
Inspection: Check for bubbles or uneven shrinkage (indicators of poor adhesion).
Field Efficiency Tip: Pre-load sleeves on fibers before cutting to minimize post-splice handling.
OTDRs: Weunion NK3200 (FTTH) / NK4000 (Long-Haul)
| Model | Core Features | Technical Specs | Ideal Use |
| NK3200 | Dual-wavelength (1310/1550nm), 34dB dynamic range | 2m event dead zone, 10,000 test result storage | FTTH, small enterprise backbones |
| NK4000 | Triple-wavelength (1310/1550/1625nm), 42dB dynamic range | AI fault analysis, Wi-Fi/Bluetooth connectivity | 5G backhaul, long-haul networks |
Testing Protocol:
①Perform bidirectional tests (launch OTDR from both fiber ends).
②Verify:
Insertion loss: ≤0.05 dB (AI10-calibrated splices).
Return loss: >55 dB (SMF) / >35 dB (MMF).
Continuity: A smooth backscatter curve (no unexpected reflections).
Weunion Insight: NK4000’s “MacroBend Detect” identifies microbends causing 0.5–1.0 dB loss.
| Issue | Root Cause | Remedy |
| High Insertion Loss | Dirty end face / misalignment | Reclean fiber, re-cleave, and review AI10’s alignment logs. |
| Bubble in Splice | Moisture/dust in the arc gap | Replace electrodes (AI9/AI10: every 500 splices) and re-clean fibers. |
| Fiber Non-Fusion | Inadequate arc power | Recalibrate arc current (use AI10’s auto-calibration) and verify fiber type. |
| Excessive Reflection | Rough end face / air gap | Recleave fiber, inspect CK12 blade (replace if worn), and reapply the sleeve. |
Splicers (AI9/AI10):
Clean V-grooves weekly using a toothpick and IPA.
Replace electrodes every 500 splices (AI10 triggers auto-reminders).
OTDRs (NK3200/NK4000):
Calibrate annually at Weunion-certified labs.
Clean connectors with the CL-08 kit before testing.
Application: FTTH (GPON/EPON), RF systems (CATV).
Weunion Solution:
AI10’s “APC Mode” (8° angle alignment).
CK12-APC cleaver (0.1° angle tolerance for APC fibers).
Outcome: Return loss >60 dB (critical for PON splitters).
Challenge: Align polarization axes with <0.5° deviation.
Weunion Innovation:
AI10’s “PM Mode” (3D axis tracking).
Custom V-grooves for PM fibers (e.g., PANDA type).
Weunion tools adhere to global benchmarks:
Splicers (AI9/AI10): IEC 61300-3-35 (splice loss), CE (safety).
OTDRs (NK3200/NK4000): ITU-T G.650.1 (fiber characterization), FCC (EMC).
Accessories (CK12/CL-08): RoHS (environmental), ISO 9001 (quality).
Client: Tier 1 telecom in Southeast Asia.
Challenge: Deploy 100G fiber backhaul with 2,000+ splices across rural and urban zones.
Splicers: AI10 (high-volume urban) + AI9 (rugged rural deployments).
Testing: NK4000 (long-haul analysis) + NK3200 (FTTH segments).
Tools: CK12 cleavers (0.2° precision) + CL-08 kits (contamination control).
Average splice loss: 0.03 dB (AI10) / 0.04 dB (AI9).
Deployment time: 25% faster (AI10’s SmartSplice reduced rework).
Network uptime: 99.99% (verified via NK4000’s AI fault prediction).
Fusion splicing excellence demands precision tools (AI9/AI10, NK3200/NK4000), technical expertise, and rigorous quality control. Weunion’s ecosystem of splicers, OTDRs, and accessories equips teams to build reliable, high-speed fiber networks.
Contact Weunion:
For splicing equipment, training, or support, email keren.qin@weunion.com.cn. Our experts deliver end-to-end solutions for modern fusion splicing challenges.
