8F OM4 MTP® Loopback Module
The 8-Fiber MTP® OM4 Loopback module is a high-precision fiber optic testing and diagnostic device designed to verify the performance of MTP®-based multi-fiber links. It provides a closed-loop return path for end-to-end testing of MTP® transceivers, patch panels, and cable infrastructure.
Constructed with OM4 multimode fiber (50/125 um, IEC Type A1a.3), this loopback module supports 10G/40G/100G/400G Ethernet parallel optics applications, including QSFP28 SR4, QSFP-DD SR8, and OSFP SR4 modules. The factory-polished and tested connector ensures repeatable low-loss performance for laboratory, production, and field-testing environments.
Description
2 Key Features
– 8-fiber MTP® connector with precision-molded MT ferrule for sub-micron alignment
– OM4 laser-optimized multimode fiber (EMB >= 4700 MHz-km at 850 nm)
– 100% factory end-face inspection per IEC 61300-3-35
– Low insertion loss (IL) and high return loss (RL) for reliable loopback testing
– Compact and lightweight form factor for easy deployment and storage
– Compatible with QSFP+, QSFP28, QSFP-DD, OSFP, and CFP2 transceivers
– Durable dust cap for connector protection during storage and transport
3 Optical Specifications
| Parameter | Value |
| Fiber Type | OM4 (50/125 um), IEC 60793-2-10 Type A1a.3 |
| Fiber Count | 8 fibers (active loopback channels) |
| Core/Cladding Diameter | 50 / 125.0 um |
| Effective Modal Bandwidth (EMB) | >= 4700 MHz-km at 850 nm |
| Bandwidth (overfilled launch) | >= 3500 MHz-km at 850 nm |
| Wavelength Range | 850 nm / 1300 nm |
| Loopback Insertion Loss | <= 0.35 dB (typical <= 0.20 dB) |
| Return Loss | >= 20 dB (PC polish) |
| Loopback Path | Fiber 1-8 internally paired (1-2, 3-4, 5-6, 7-8) |
4 Connector Specifications
| Parameter | Value |
| Connector Type | MTP® (Multi-fiber Push-On) |
| Ferrule Type | MT (Mechanical Transfer), precision-molded |
| Fiber Configuration | 8-fiber, single row |
| Connector Gender | Female (no guide pins) or Male (with guide pins) |
| Polish Type | PC (Physical Contact) |
| Ferrule Material | PPS (Polyphenylene Sulfide) |
| Guide Pin Diameter | 0.7 mm (male version) |
| Keying | Key Up / Key Down (per adapter) |
| Mating Durability | >= 500 mating cycles |
| Spring Force | 10.0 +/- 0.5 N per connector |
| Insertion Force | <= 15 N (typical) |
5 End-Face Geometry (IEC 61300-3-35)
| Parameter | Specification |
| Radius of Curvature (X-axis) | 8 – 25 mm |
| Radius of Curvature (Y-axis) | 8 – 25 mm |
| Fiber Undercut/Protrusion | <= +/- 50 nm |
| Apex Offset | <= 50 um |
| Scratch/Dig | 20/10 per MIL-PRF-15703B |
6 Dimension Specifications
7 Environmental Specifications
| Parameter | Value |
| Operating Temperature | -10 deg C to +60 deg C |
| Storage Temperature | -40 deg C to +85 deg C |
| Operating Humidity | 10% to 95% RH (non-condensing) |
| Thermal Shock | -40 deg C to +85 deg C, 100 cycles (Telcordia GR-326) |
| Damp Heat | 85 deg C / 85% RH, 1000 hours |
| Vibration | 10 – 500 Hz, 1.5 g, per IEC 60068-2-6 |
| Shock | 50 g, 11 ms, half-sine, per IEC 60068-2-27 |
| Flame Rating | LSZH / OFNP / Plenum (UL 910 / IEC 60332-1) |
8，Polarity
9 Applications
– Transceiver module testing and validation (QSFP28 SR4, QSFP-DD SR8, OSFP)
– MTP® patch panel and cassette loopback verification
– Fiber optic link troubleshooting and fault isolation
– Production line end-of-line testing for MTP®-based assemblies
– Laboratory and R&D characterization of parallel optics
– Network commissioning and acceptance testing (40G / 100G / 400G)
– Automated optical test systems (AOT) for high-volume manufacturing
10 Standards & Compliance
| Standard | Description |
| IEC 61754-7 | Fibre optic interconnecting devices – MTP® connector interface |
| IEC 61300-3-4 | Fibre optic interconnecting devices – Optical attenuation test |
| IEC 61300-3-35 | Fibre optic interconnecting devices – Visual inspection of end face |
| TIA/EIA-604-5 (FOCIS-5) | Fiber Optic Connector Intermateability Standard – MTP® |
| TIA/EIA-568-D.3 | Optical Fiber Cabling Components Standard |
| ISO/IEC 11801 | Information technology – Generic cabling for customer premises |
| Telcordia GR-326-CORE | Generic Requirements for Singlemode Optical Connectors |
| RoHS 2.0 (2011/65/EU) | Restriction of Hazardous Substances Directive |
| REACH (EC 1907/2006) | Registration, Evaluation, Authorisation of Chemicals |
11 Ordering Information
| Part Number | Description | Notes |
| LB-MTP®-8F-OM4-F | 8F MTP® OM4 Loopback, Female | No guide pins |
| LB-MTP®-8F-OM4-M | 8F MTP® OM4 Loopback, Male | With guide pins |
| LB-MTP®-8F-OM4-F-APC | 8F MTP® OM4 Loopback, Female, APC | Angled polish |
| LB-MTP®-8F-OM4-M-APC | 8F MTP® OM4 Loopback, Male, APC | Angled polish |
Custom configurations (cable length, polarity, boot type) available upon request.
