12F OM4 MTP® Loopback
The 12-Fiber OM4 MTP® Female Loopback Module is a high-performance passive multimode fiber optic test component designed to route transmitted optical lanes back into receiving lanes within a single MTP®-12 interface. It provides a controlled, closed optical return path for port verification, transceiver validation, burn-in testing, and network troubleshooting in high-speed parallel optics environments.
Built with laser-optimized OM4 50/125 um multimode fiber, this module delivers superior bandwidth performance compared to OM3, with an effective modal bandwidth of 4700 MHz-km at 850 nm. It is engineered for 40G, 100G, and emerging 400G multimode applications, supporting QSFP+, QSFP28, QSFP-DD, CXP, and CFP2 transceiver platforms. The Erika Violet connector shell provides immediate visual identification per TIA-598-C, distinguishing OM4 from other multimode fiber grades. The compact push-pull design enables rapid insertion and extraction without additional tooling.
Description
Key Features
- 12-fiber MTP® Female connector optimized for 40G/100G/400G multimode parallel optics
- Laser-optimized OM4 50/125 um multimode fiber with 4700 MHz-km EMB at 850 nm
- Extended reach: supports up to 150 m at 100G-SR4 and 550 m at 10G per IEEE 802.3
- UPC flat polish with precision MT ferrule for optimal multimode optical performance
- Push-pull coupling mechanism for tool-free insertion and extraction
- Low insertion loss (<= 0.50 dB max, standard grade) for reliable test accuracy
- High return loss (>= 25 dB typical) for clean signal reflection
- Configurable polarity: Type A, Type B, Type C, or custom mapping per project needs
- Erika Violet connector shell per TIA-598-C for immediate OM4 multimode identification
- LSZH (Low Smoke Zero Halogen) housing for enhanced fire safety compliance
- Backward compatible with OM3 cabling infrastructure for mixed-fiber environments
- Protective dust cap included; optional tethered cap available for field use
- RoHS and REACH compliant materials throughout
Technical Specifications
1 General Parameters
| Parameter | Specification |
| Product Type | MTP® Loopback Module (Multimode) |
| Fiber Count | 12 Fibers |
| Fiber Type | OM4 Multimode 50/125 um (laser-optimized, per IEC 60793-2-10 A1a.3) |
| Connector Type | MTP®-12 (Female / Male available) |
| Connector Gender | Female (no guide pins) standard; Male (with guide pins) optional |
| Connector Shell Color | Erika Violet (OM4 identification per TIA-598-C) |
| Polish Type | UPC (Ultra Physical Contact, flat polish) |
| Coupling Mechanism | Push-pull design |
| Dust Cap | Protective dust cap included; tethered cap optional |
| Guide Pin Diameter | 0.7 mm (male connector) |
| Ferrule Type | 12-fiber MT ferrule (6.4 mm x 2.5 mm ceramic) |
| Weight (typical) | < 5 g per module (without pigtail) |
2 Optical Performance
| Parameter | Low Loss | Standard | Unit |
| Typical Insertion Loss | 0.15 | 0.25 | dB |
| Maximum Insertion Loss | 0.50 | 0.75 | dB |
| Return Loss | >= 30 | >= 25 | dB |
| Operating Wavelength | 850 / 1300 | 850 / 1300 | nm |
| Attenuation Uniformity (lane-to-lane) | <= 0.3 | <= 0.5 | dB |
3 OM4 Fiber Characteristics
| Parameter | Specification |
| Core / Cladding Diameter | 50.0 +/- 2.5 / 125.0 +/- 1.0 um |
| Effective Modal Bandwidth (EMB) @ 850 nm | >= 4700 MHz-km |
| Overfilled Launch Bandwidth @ 850 nm | >= 3500 MHz-km |
| Overfilled Launch Bandwidth @ 1300 nm | >= 500 MHz-km |
| Maximum Attenuation @ 850 nm | 3.0 dB/km |
| Maximum Attenuation @ 1300 nm | 1.0 dB/km |
| Differential Mode Delay (DMD) | Per IEC 60793-1-49 |
| Numerical Aperture (NA) | 0.20 +/- 0.015 |
| Macro-bend Loss @ 850 nm (15 mm, 2 turns) | <= 0.5 dB |
| Jacket Color | Erika Violet (per TIA-598-C) |
| Minimum Bend Radius (short-term) | 30 mm |
| Minimum Bend Radius (long-term) | 15 mm |
4 Transmission Distance Capability
The following table lists the maximum supported transmission distances for common transceiver types when using OM4 fiber, providing context for test environment design:
| Transceiver Type | Data Rate | Max Distance (OM4) | Fibers Used |
| 10GBASE-SR (SFP+) | 10 Gbps | 400 m | 2 (duplex) |
| 40G-SR4 (QSFP+) | 40 Gbps | 150 m | 8 (4 TX + 4 RX) |
| 100G-SR4 (QSFP28) | 100 Gbps | 150 m | 8 (4 TX + 4 RX) |
| 100G-SR10 (CXP) | 100 Gbps | 100 m | 20 (10 TX + 10 RX) |
| 200G-SR4 (QSFP56) | 200 Gbps | 100 m | 8 (4 TX + 4 RX) |
| 400G-SR8 (QSFP-DD) | 400 Gbps | 100 m | 16 (8 TX + 8 RX) |
| 400G-SR4.2 (QSFP-DD) | 400 Gbps | 150 m | 8 (4 TX + 4 RX) |
5 Environmental Specifications
| Parameter | Specification |
| Operating Temperature | -40 degC to +75 degC |
| Storage Temperature | -40 degC to +85 degC |
| Thermal Shock | -40 degC to +75 degC, 20 cycles per IEC 61300-2-14 |
| Damp Heat (steady state) | 85 degC / 85% RH, 1000 hours per IEC 61300-2-18 |
| Humidity (operating) | 5% to 95% RH (non-condensing) |
| Altitude | Up to 3,000 m |
| Salt Spray | IEC 61300-2-25 compliant (optional) |
Dimension Specifications
Fiber Mapping & Polarity
Correct fiber mapping is critical for valid loopback test results. The module routes transmit (TX) lanes back to corresponding receive (RX) lanes through a defined internal fiber path. The mapping must be matched to the target transceiver architecture to produce meaningful diagnostic data.
1 Available Polarity Options
2 Standard 12-Fiber Active Lane Mapping
In standard 40G-SR4 and 100G-SR4 applications, only 8 of the 12 fibers carry active signals. The remaining 4 fibers (positions 5-8) are physically present but optically inactive. The loopback module maps active lanes as follows:
| Application | TX Lanes (Fiber Position) | RX Lanes (Fiber Position) | Unused Fibers |
| 40G-SR4 (QSFP+) | 1, 2, 3, 4 | 9, 10, 11, 12 | 5, 6, 7, 8 |
| 100G-SR4 (QSFP28) | 1, 2, 3, 4 | 9, 10, 11, 12 | 5, 6, 7, 8 |
| 200G-SR4 (QSFP56) | 1, 2, 3, 4 | 9, 10, 11, 12 | 5, 6, 7, 8 |
| 100G-SR10 (CXP) | 1-10 | 1-10 (loopback all) | 11, 12 |
3 Key Position Reference
The MTP®-12 connector features a keying notch on the top side and a white dot indicating fiber position 1. When mating with a transceiver (which typically has a male MTP® interface with guide pins), the loopback module (female) must be oriented with the key aligned correctly. Incorrect keying can damage the ferrule or produce false test results.
| Orientation | Module Key | Transceiver Key | Mating Condition |
| Type A adapter | Key-Up on module | Key-Down on transceiver | Key-Up to Key-Down (normal mating) |
| Type B adapter | Key-Up on both sides | Key-Up to Key-Up | Flipped orientation for Type B polarity |
IMTP®rtant: Always confirm the internal mapping drawing with the supplier before bulk procurement. An incorrect mapping will produce misleading test results, false failure reports, and wasted troubleshooting time.
Transceiver Compatibility Matrix
The following table lists verified transceiver form factors and interface types compatible with the 12F OM4 MTP® Loopback Module:
| Form Factor | Interface | Data Rate | Compatibility |
| SFP+ | Duplex LC | 10 Gbps | Requires MTP®-to-LC breakout cable |
| QSFP+ | MTP®-12 | 40 Gbps | Direct connection (native) |
| QSFP28 | MTP®-12 | 100 Gbps | Direct connection (native) |
| QSFP56 | MTP®-12 | 200 Gbps | Direct connection (native) |
| QSFP-DD | MTP®-12/16 | 400 Gbps | Direct (SR4.2); breakout required (SR8) |
| CXP | MTP®-12 x2 | 100/120 Gbps | Direct connection on each MTP®-12 port |
| CFP2 | MTP®-12 | 100 Gbps | Direct connection (native) |
| OSFP | MTP®-12/16 | 400 Gbps | Direct (SR4); breakout required (SR8) |
Standards & Compliance
| Standard | Description |
| IEC 61754-7 | Fibre optic connectors – MTP® connector interface standard |
| IEC 60793-2-10 | Optical fibres – Part 2-10: Product specifications – A1a.3 (OM4) |
| TIA-492AAAD | OM4 multimode fiber specification (50/125 um, laser-optimized) |
| TIA-598-C | Optical fiber cable color coding and identification |
| TIA-604-5 | Fiber optic connector intermateability – MTP® type |
| ISO/IEC 11801 | Generic cabling for customer premises (OM4 class) |
| IEEE 802.3 | Ethernet standard – multimode reach and link budget definitions |
| IEC 61300-2-x | Basic test procedures: vibration, shock, thermal, humidity, static load |
| IEC 61300-3-4 | Attenuation / insertion loss measurement method |
| IEC 61300-3-35 | Visual inspection of fiber optic connector end-faces |
| UL 94 V-0 | Flammability rating for housing material |
| RoHS 2011/65/EU | Restriction of Hazardous Substances Directive |
| REACH EC 1907/2006 | Registration, Evaluation, Authorisation of Chemicals |
Ordering Information
To place an order or request a quotation, please specify the following parameters:
| Parameter | Options | Default |
| Fiber Count | 12 | 12 |
| Fiber Type | OM4 (50/125 um, laser-optimized multimode) | OM4 |
| Connector Gender | Female (standard), Male (optional) | Female |
| Polish Type | UPC | UPC |
| Polarity | Type A, Type B, Type C, Custom (per drawing) | Type A |
| Performance Grade | Low Loss, Standard | Standard |
| Dust Cap | Standard (loose), Tethered (attached) | Standard |
| Labeling | Standard, Custom (laser-etched or printed) | Standard |
| Packaging | Individual anti-static bag, foam tray, bulk carton | Individual bag |
| Minimum Order Quantity | 1 pc (sample); 10 pcs (production) | 1 pc |
Part Number Convention: MTP®12-LB-OM4-[Gender]-[Polish]-[Polarity]-[Grade]-[Options]
Example: MTP®12-LB-OM4-F-UPC-A-STD = 12F OM4 MTP® Loopback, Female, UPC polish, Type A polarity, Standard grade, standard dust cap
Example: MTP®12-LB-OM4-F-UPC-B-LL-T = 12F OM4 MTP® Loopback, Female, UPC polish, Type B polarity, Low Loss grade, tethered dust cap
Applications
The 12F OM4 MTP® Loopback Module addresses a broad spectrum of multimode test and verification requirements across data center, enterprise, and telecommunications environments:
| Application | Description |
| 40G Transceiver Verification | Verify TX/RX functionality and lane balance of 40G-SR4 QSFP+ transceivers in multimode test environments |
| 100G Transceiver Validation | Full lane-level diagnostics for 100G-SR4 QSFP28 transceivers including power level and BER threshold verification |
| Switch / Router Port Commissioning | Validate MTP® port behavior and signal integrity before live network patching in data center spine-leaf architectures |
| Equipment Burn-in & Aging | Continuous optical loopback for extended reliability and stress testing during factory acceptance procedures |
| Multimode Link Troubleshooting | Rapid isolation of equipment-side faults from cabling issues in deployed OM3/OM4 multimode infrastructure |
| Lab Protocol Simulation | Controlled multimode test paths for parallel optics protocol validation and system integration testing |
| Incoming Quality Inspection | Repeatable acceptance routines for optical transceiver and equipment manufacturers |
| Mixed OM3/OM4 Environment Testing | Validate backward compatibility and performance margins in networks with mixed OM3 and OM4 fiber plant |
Handling, Storage & Maintenance
1 Handling Precautions
- Always use the protective dust cap when the module is not mated to prevent end-face contamination.
- Inspect the MTP® connector end-face with a fiber inspection microscope (per IEC 61300-3-35) before each insertion. Reject modules with visible scratches, pits, or contamination.
- Clean the connector end-face using an MTP®-specific cleaning tool (cassette cleaner, click cleaner, or wet-dry wipe method) before mating if contamination is detected.
- Do not touch the ferrule end-face with bare fingers. Skin oils, lotions, and particulates degrade optical performance and can cause permanent damage.
- Verify the Erika Violet shell color matches the target OM4 multimode adapter. Do not mate OM4 connectors with singlemode (yellow/black) adapters or OM1/OM2 (orange/beige) infrastructure.
- Align the keying notch correctly before insertion. Forced insertion with misaligned keys can damage the guide pins and ferrule.
2 Storage Requirements
- Store in original anti-static packaging in a clean, dry, temperature-controlled environment.
- Maintain storage temperature between -40 degC and +85 degC.
- Avoid exposure to direct sunlight, high humidity (> 95% RH), and corrosive atmospheres.
- Do not stack heavy objects on top of stored modules to prevent housing deformation.
3 Maintenance Schedule
| Condition | Action Required |
| Before each use | Visual inspection with microscope; clean if contamination detected |
| After 100 mating cycles | Detailed end-face inspection per IEC 61300-3-35 Grade B |
| After 500 mating cycles | Full inspection; re-polish or replace if degradation observed |
| Annual (if stored) | Visual inspection; verify dust cap integrity; check for housing discoloration |
| After field incident | Immediate inspection; test insertion loss; replace if out of specification |
