Fiber optic connectors - types & overview

The global volume of data is increasing at an unprecedented rate. With digitalization on the rise, the demands on data centers are intensifying. These facilities must handle vast amounts of data that require fast, secure, and reliable transmission. Consequently, the performance of data center components, such as fiber optic connectors, has become increasingly critical, as they play a key role in signal transmission.

High-quality fiber optic connectors are essential for achieving maximum data transmission rates and ensuring continuous system availability. To meet these demands, it is crucial to minimize the impact of connectors on key parameters such as insertion loss (dB) and return loss (dB).

Additional requirements for fiber optic connectors include: 

• Ease of handling
• Mechanical durability for continuous operation
• Compact design to minimize space usage

Given these considerations, selecting, using, and maintaining fiber optic connectors properly is more important than ever.

Optical fiber cables can be equipped with a wide variety of connectors. Below is an overview of the most commonly used types:

LC connector

The LC connector is a compact, small-form-factor system compliant with DIN EN 61754-20. The latest generation of LC Compact connectors features a streamlined housing that ensures optimal fiber protection and reliable strain relief for different cable types. 

• Versions: Multimode and singlemode, standard and angled (oblique) cuts. LC connectors are available in PC (Physical Contact) and APC (Angled Physical Contact) variants.
• Ferrule: Made of zirconia ceramic with a diameter of 1.25 mm.

MPO/MTP^® connector

MPO stands for "Multi-fiber Push-On" and refers to connectors designed for multi-fiber cables, typically accommodating 6, 8, 12, or 24 fibers. The MPO connector is often called the MTP^® connector, a registered trademark of US-Conec Ltd.

SC connector

The SC connector is a push-on fiber optic connector that complies with DIN IEC 61754-15 standards, making it suitable for telecommunications, data centers, LAN cabling, and active component connections.

• Versions: Available in multimode and singlemode, with standard and angled cuts. SC connectors come in PC and APC variants.
• Special Features: The SC/APC connector features an angled (8° or 9°) polished ferrule face that minimizes reflected light, significantly reducing propagation and increasing return loss. APC connectors are primarily used with singlemode cables.
• Ferrule: Made of zirconia ceramic with a diameter of 2.5 mm.

E-2000^® connector

The E-2000^® is a push-on fiber optic connector with a push-pull locking mechanism and an integrated self-closing dust protection flap, compliant with IEC 61754-15 standards.

• Design: Supports multimode and singlemode fibers, with both standard and angled cuts. Available in PC and APC variants.
• Ferrule: Made of zirconia ceramic with a diameter of 2.5 mm.

Expanded beam connectors

Expanded beam connectors are designed to expand the optical beam, making them less sensitive to contamination compared to conventional push-on connectors. When paired with high-quality cables, these connectors excel in harsh environmental conditions.

Connector technology for optical fibers (OF):

APC (Angled Polished Contact)
Some fiber-optic connectors are available in both PC (Physical Contact) and APC (Angled Physical Contact) versions. In the APC variant, the fiber endface is ground at an angle, typically 8°, which prevents reflected light from propagating. This significantly minimizes reflections.

Duplex vs Simplex
Duplex: A transmission mode where data is sent and received simultaneously in both directions. Duplex transmission is also referred to as two-way transmission, as defined by DIN standards.
Simplex: A transmission mode where data flows in only one direction, without a return path or channel. This is known as one-way transmission according to DIN standards.

Ferrule 
The ferrule is the connector pin, typically made of ceramic, that ensures precise axial alignment of the fiber within the connector.

Multimode fiber (MMF)
Multimode fibers allow multiple light waves (modes) to propagate through their core. The number of modes is determined by the size of the fiber core. Common dimensions include 50/125 µm and 62.5/125 µm. Multimode fibers are classified into categories such as OM1, OM2, OM3, OM4, and OM5.

Singlemode fiber (SMF)
Singlemode fibers allow the propagation of only one light wave (mode) through their core. These fibers typically have a core size of 9/125 μm.

The performance of fiber-optic cabling relies heavily on the cleanliness of the fiber ends. Even tiny particles of dirt, grease, or dust can drastically reduce the transmission quality of a fiber-optic connection. Proper cleaning is essential to maintain optimal performance.

Depending on the type and design of the fiber-optic connector, specialized tools and technical expertise may be required for effective cleaning.

For more details and a comprehensive overview of tools for cleaning both loose and installed optical fiber connectors, refer to the provided resources.

Cable assembly involves producing ready to connect cables, cable bundles, and complete wiring harnesses by equipping them with connectors, contacts, or fiber end sleeves.

Rosenberger OSI is one of Europe’s leading manufacturers of assembled MTP^® cables, assembling approximately 4 million push-on connectors annually at our production and logistics centers in Taksony, Hungary, and Apodaca, Mexico. We utilize a variety of optical fiber connectors for cable assembly, including LC, SC, MDC, MTP^®/MPO, MU, MXC^®, E-2000^®, FC, ST, and expanded beam connectors.

With advanced manufacturing processes and extensive production capabilities, we provide rapid delivery regardless of batch size.

• 4,700m² production area
• 3,400m² storage area

Our superior production standards and high-quality products enable seamless installation and long-term performance. We exclusively use our own push-on connectors or those from reputable, high-quality manufacturers. All connectors meet or exceed international standards, ensuring compliance with applicable specifications.

At Rosenberger OSI, we adhere to stringent assembly standards and often exceed them. For instance, the insertion loss (IL) of our PURE-quality 50 µm multimode cables outperforms the most demanding performance requirements of IEC 61755-5 Ed. 1.0 CD Grade CM.