1. Overview of Optical Fiber Patch Cord
1.1 Definition and Function
Optical Fiber Patch Cord is the cable assemblies with connector plugs at both ends, used to achieve flexible and plug-and-play fiber optic connections between devices or between devices and fiber optic patch panels. They serve as a “bridge” that enables flexible scheduling and distribution of optical signals, responsible for accurately transmitting light signals over short distances (typically from a few meters to several tens of meters).
To meet these connection needs across various scenarios, manufacturers like Baudcom offer comprehensive patch cord solutions. Their Fiber Optical Patch Cords, available with popular connector types like FC, LC, SC, and ST, serve as reliable "bridges," ensuring accurate and low-loss optical signal transmission for flexible network configurations.
1.2 Applications in Modern Communication Networks
Optical fiber patch cords are the “capillaries” of modern optical communication networks, with extremely wide applications:
Data centers: high-speed interconnection among servers, switches, and storage devices.
Telecommunication networks: connecting transmission equipment (such as OLTs and routers) for backbone networks, metropolitan area networks, and FTTH access.
Broadcast and television: connecting equipment involved in high-definition video production and transmission.
Other fields: such as medical imaging devices, industrial control networks, and security monitoring systems.
1.3 Brief Development History
Their development closely follows fiber optic technology: emerging in the 1970s with the rise of optical communication, characterized by simple structures; single-mode fiber optic jumpers appeared in the 1980s; interface standardization occurred in the 1990s (such as FC, SC, LC); since the 21st century, to meet the needs of high-density and high-speed data centers, the development has moved toward miniaturization (such as LC, MTP), low loss, and intelligent features.
2. Working Principles and Performance Indicators
2.1 Working Principles
Fiber Optical Patch Cord itself does not generate signals; its core function is to transmit light signals with low loss. The working process is based on the principle of total internal reflection of light:
Transmission: The light emitter (such as a laser diode) converts electrical signals into light signals.
Propagation: The light signals travel forward within the fiber core of the patch cord, through total internal reflection at the interface between the core and cladding.
Reception: The light receiver (such as a photodetector) converts the received light signals back into electrical signals.
2.2 Key Performance Indicators
Insertion Loss: The power attenuation of the light signal after passing through the patch cord. The smaller the value, the better, with typical values less than 0.3dB.
Return Loss: The loss caused by light signals being reflected back at the connector end face. The larger the value, the better, indicating less reflection.
Interchangeability and Repeated Plug/Unplug Performance: Ensures that the connector can maintain stable performance after multiple plug-ins and exchanges.
High-quality patch cords are engineered to excel in these parameters. For example, the Baudcom Fiber Optical Patch Cords specify an insertion loss of ≤0.3dB and a return loss of ≥55dB (UPC) / ≥60dB (APC) for single-mode fibers, meeting the stringent requirements for efficient signal transmission in modern networks. Their durability, verified by ≥1000 plug cycles, ensures long-term reliability.
2.3 Major Factors Affecting Optical Loss
Intrinsic Factors: Absorption and scattering within the fiber material.
Connection Factors: Gaps, misalignment, contamination, or poor polishing of the connector end faces.
Bending Loss: Excessively small bending radius of the fiber causes leakage of the light signal.
Length: The fiber itself has an attenuation coefficient; longer lengths result in greater total loss.
Core Structural Features
3. Core Structural Features
Fiber Optical Patch Cord is mainly composed of three parts: the fiber itself, the connector plug, and the outer sheath.
|
Structural Components |
Functions and Characteristics |
Common Types/Materials |
|
Fiber Optical Patch Cord Core |
The channel for transmitting light signals; its size and type determine the transmission mode (single-mode/multimode) and performance. |
Single-mode (SM): 8-10μm; Multimode (MM): 50/62.5μm; Material: high-purity silica dioxide |
|
Fiber Optical Patch Cord Cladding |
Wraps around the core; achieves total internal reflection through its refractive index difference with the core, constraining light transmission within the core. |
Usually doped silica dioxide, approximately 125μm in diameter |
|
Connector Plug |
Interface at both ends of the patch cord; ensures precise alignment and reliable connection with device ports. |
LC, SC, FC, ST, MTP/MPO, etc. |
|
Outer Sheath |
Protects the internal fiber structure, providing mechanical strength and environmental protection. |
PVC (general purpose), LSZH (low smoke zero halogen, used in data centers), OFNP (Plenum grade, used in ventilation spaces) |
4. Main Types and Selection Guide
4.1 Classification by Fiber Mode
This is the most basic classification, directly determining the application scenario:
Single-mode Fiber Optical Patch Cord: The core is thin (8-10μm), transmitting only one mode. It has low dispersion and extremely low loss, suitable for long-distance, high-capacity backbone networks, metropolitan area networks, and FTTH.
Multimode Fiber Optical Patch Cord: The core is thicker (50/62.5μm), transmitting multiple modes. It has higher modal dispersion and higher loss, but the cost of light sources is low (commonly using VCSEL lasers), making it suitable for short-distance, high-bandwidth data center internal connections and local area networks.
|
Features |
Single-Mode Fiber Optical Patch Cord |
Multimode Fiber Optical Patch Cord |
|
Core Diameter |
8~10 μm |
50 or 62.5 μm |
|
Transmission Distance |
Long-distance (up to dozens to hundreds of kilometers) |
Short-distance (usually tens of meters to hundreds of meters) |
|
Light Source |
Laser Diode (LD) |
Light-emitting diode (LED) or Vertical-Cavity Surface-Emitting Laser (VCSEL) |
|
Bandwidth |
Extremely high |
High, but limited by modal dispersion |
|
Typical Applications |
Telecom backbone networks, FTTH, long-distance data transmission |
Internal data centers, enterprise campus networks, equipment interconnection in data centers |
|
Cost |
Higher cost for optical modules |
Relatively lower cost for optical modules |
4.2 Classification by Connector Type
Connectors are the “face” of the Fiber Optical Patch Cord; different types of interfaces have different sizes and locking mechanisms.
LC type: Small square head, push-pull lock mechanism. It is the preferred choice for high-density designs and is currently the mainstream in data centers and enterprise networks.
SC type: Large square head, push-pull lock mechanism. Offers stable performance and is widely used in early projects and patch panels.
FC type: Circular threaded head with spiral locking. Provides secure fastening and vibration resistance; mainly used for test equipment and traditional telecommunications networks.
ST type: Circular bayonet head, similar to BNC. Gradually replaced by LC/SC, commonly seen in old network upgrades.
MTP/MPO type: Multi-fiber connector; one head can connect 12/24/48 fibers. Designed for 40G/100G/400G parallel optical transmission, used in high-density pre-terminated systems in data centers.
4.3 Selection Guide
Choosing the appropriate Fiber Optical Patch Cord requires comprehensive consideration of:
Transmission distance and bandwidth: For long distances and high speeds, select single-mode; for short distances and high cost-performance, choose multimode (OM3/OM4/OM5).
Connector type: Select based on device port type. LC is preferred in high-density environments; MTP/MPO is necessary for high-speed parallel links.
Connector polishing type: PC/UPC (blue connector) is suitable for most scenarios; APC (green connector, angled polishing) offers better return loss and is mainly used in FTTH, PON, and other systems sensitive to reflections.
Sheath material: PVC or LSZH for indoor environments like data centers; OFNP Plenum grade for spaces such as ventilation ducts.
Length: Determine based on the actual routing path, leaving an appropriate margin to avoid excessive tension or winding.
5. Application Scene Details
5.1 Data Center
This is one of the scenarios with the largest consumption of Fiber Optical Patch Cords. The core requirements are high density and high speed.
Device interconnection: Using LC Fiber Optical Patch Cords to connect top-of-rack (TOR) switches with servers.
Parallel optical: Using MTP/MPO Fiber Optical Patch Cords to achieve 40G/100G/400G interconnects between switches in Spine-Leaf architecture.
Pre-connection system: MTP Fiber Optical Patch Cords are the key components for pre-connected trunk cables between optical main distribution frames and optical distribution frames.
5.2 Fiber to the Home (FTTH)
At the user terminal, short-distance single-mode SC/APC or LC/APC Fiber Optical Patch Cords connect the home ONT (optical modem) with the optical information socket (OBD) on the wall. APC connectors can maximize reflection reduction and ensure signal quality.
5.3 Telecom Equipment Room and Enterprise Network
Line dispatching: Using Fiber Optical Patch Cords on ODFs for flexible optical path configuration and dispatching.
Device interconnection: Connecting transmission devices, routers, switches, and others.
6. Development Trends
Higher density and smaller size: With LC becoming the absolute mainstream and the widespread adoption of MTP, the port density within a given space continues to increase. Emerging smaller connectors such as CS and SN are also being explored.
Supporting higher speeds: In response to the demand for 400G/800G and even 1.6T Ethernet, Fiber Optical Patch Cords that support higher bandwidth multimode optical fibers (OM5) and low-loss single-mode fibers have become standard configurations.
Intelligent management: Smart Fiber Optical Patch Cords integrated with electronic labels (such as RFID), combined with management systems, enable real-time monitoring of physical links, automatic resource discovery, and rapid fault localization, greatly improving operation and maintenance efficiency.
Green and environmentally friendly: The application of LSZH (Low Smoke Zero Halogen) sheath materials is becoming increasingly common, enhancing fire safety in equipment rooms.
7. Conclusion
As fundamental components of the optical network physical layer, the performance and quality of Fiber Optical Patch Cords directly affect the stability and reliability of the entire communication system. From simple signal connectors to today’s key parts supporting ultra-high density, ultra-high speeds, and intelligent management, Fiber Optical Patch Cord technology is still continuously evolving. Proper understanding of their types and features, coupled with rational selection, is an indispensable part of building efficient and reliable optical communication networks. In the future, it will continue to serve as the “precise link” of the information highway, playing a cornerstone role in digital transformation.