A fiber optic connector is a detachable active component for linking separate optical fibers. It precisely aligns two fiber end faces to maximize light energy coupling from the transmitting fiber to the receiving fiber, while minimizing signal interference introduced into the optical link. Its overall quality directly decides the reliability and performance of optical transmission systems.
Industry Development Status
Domestic fiber optic communication has entered large-scale practical application with expanding coverage. Local connectors are mostly assembled from imported ceramic ferrules and metal spare parts, or manufactured with imported core production technology and equipment, with FC-type as the mainstream model. Three core optimization suggestions are proposed for the industry:
| 1 | Unified Standardization | Global mainstream economies have mature national standards recognized by IEC. Unified national specifications for connector models shall be released as official technical and network-access requirements to avoid model chaos and simplify maintenance. |
| 2 | Cross-device Compatibility | Users need to match connector types across transmission hardware, auxiliary gear and testing instruments during procurement. Adapters or patch cords are prepared in advance if model differences exist between new and existing equipment. |
| 3 | Rational Production & Selection | Manufacturers develop standardized products centered on common 2.5mm ferrules and matching sleeves to fit domestic demands; purchasers select models balancing performance, cost and upgradability for fiber-to-home and high-speed LAN construction. |
Core Performance Indicators
Key evaluation dimensions cover optical performance, interchangeability, repeatability, tensile strength, temperature adaptability and plug lifespan, detailed as below:
| 1 | Insertion Loss | Power loss caused by connector access; standard requirement ≤0.5dB (lower values perform better) |
| 2 | Return Loss | Capability to suppress reflected light; basic threshold ≥25dB; polished premium connectors reach ≥45dB |
| 3 | Interchangeability & Repeatability | Generic passive parts of the same type can be freely combined and reused; extra loss from repeated mating stays below 0.2dB |
| 4 | Tensile Strength | Finished connectors withstand pulling force no less than 90N |
| 5 | Operating Temperature | Stable operation between -40℃ ~ +70℃ |
| 6 | Plug Cycle Life | Minimum 1000 reliable insert/extract operations |
End Face Polishing Types (PC/UPC/APC)
The suffix after connector codes (e.g. FC/PC, SC/PC) marks polishing craft. Comparison of three mainstream types:
| 1 | PC (Physical Contact) | Flat end face, widely deployed in telecom equipment |
| 2 | UPC (Ultra Physical Contact) | Lower insertion loss for precision internal jumper wiring |
| 3 | APC (Angled Physical Contact) | Angled end face for analog CATV/broadcast systems to eliminate screen ghosting from back reflection; unavailable for multimode fiber |
Reflection suppression ranking: PC ＜ UPC ＜ APC
General Structural Design
Nearly all mainstream fiber connectors adopt a 3-part precision assembly: two ferrules + one coupling sleeve. Optical fibers are fixed inside ferrules with polished end faces for alignment inside the sleeve. Ferrules are made of metal or nonmetal, with stress-relief structures at the cable end. Coupling sleeves use ceramic/bronze split cylinders paired with flanges for mounting; ultra-high machining precision guarantees micron-level fiber core alignment.
Common Classification & Mainstream Types
Classification rules and mainstream styles:
| 1 | By transmission medium | Single-mode, multi-mode, plastic fiber variants |
| 2 | By structural form | FC, SC, ST, LC, DIN, MU, MT-RJ, etc. |
| 3 | By end face shape | PC, UPC, APC |
| 4 | By fiber core count | Single-core, multi-core (e.g. MT-RJ) |
Mainstream Connector Types & Features
| 1 | FC | Threaded metal reinforced structure, simple sturdy design, improved spherical PC end face cuts reflection flaws |
| 2 | SC | Square push-pull latch design, low insertion fluctuation, high mounting density for network device ports |
| 3 | ST | Bayonet locking for wiring frames and modular distribution terminals |
| 4 | DIN47256 | Built-in pressure-control spring to avoid end face damage from over insertion force |
| 5 | MT-RJ | Dual-core RJ-style latch for high-density data transmission |
| 6 | LC | 1.25mm mini ferrule (half the size of FC/SC), dominant for high-density single-mode wiring |
| 7 | MU | Ultra-compact self-latching design for compact cabinet deployment |
MC Series Reference Parameters
| MC/UPC Specs | ||
| 1 | Typical Insertion Loss | ≤0.30dB |
| 2 | Random Insertion Loss | ≤0.50dB |
| 3 | Return Loss | ≥40dB |
| MC/APC Specs | ||
| 1 | Typical Insertion Loss | ≤0.30dB |
| 2 | Random Insertion Loss | ≤0.50dB |
| 3 | Return Loss | ≥60dB |
Supplementary Note
FICON, a historic mainframe channel standard built on fiber channel protocols, upgrades half-duplex 17MB/s ESCON to full-duplex 100MB/s for high-frequency I/O tasks. Standard fiber connectors require insertion loss＜0.5dB, stable repeat performance over 500 plug cycles and low back-reflection for high-bandwidth transmission.
Note: All information above is for reference only. For further details and customized inspection solutions, please contact us at any time.
