Side-by-Side Comparison
Fiber Connectors
LC vs. ST
Comparing 2 standards across 10 specifications. 10 key differences identified.
Comparing:
LC
ST
The LC connector (Lucent Connector, TIA-604-10 / FOCIS-10) is a small form-factor (SFF) optical connector utilizing a 1.25 mm ceramic ferrule and an RJ45-style push-pull latching clip, widely used in enterprise datacenters and optical transceivers (SFP/SFP+/SFP28).
The ST connector (Straight Tip, TIA-604-2 / FOCIS-2) is a legacy fiber optic connector developed by AT&T Bell Laboratories. Featuring a 2.5 mm spring-loaded ceramic ferrule with a BNC-style twist-and-lock metal bayonet coupling, it remains common in industrial networks and campus multi-mode backbones.
Specification Comparison Table
10 Parameters| Parameter / Spec | ||
|---|---|---|
|
Standard / FOCIS
|
TIA-604-10-B (FOCIS-10) / IEC 61754-20 | TIA-604-2-B (FOCIS-2) / IEC 61754-2 |
|
Ferrule Diameter
|
1.25 mm | 2.5 mm |
|
Ferrule Material
|
Zirconia ceramic | Zirconia ceramic or stainless alloy |
|
Latching Mechanism
|
Push-pull with retention clip (RJ45-style) | Bayonet twist-lock (BNC-style keying) |
|
Fiber Modes Supported
|
Single-Mode (OS1/OS2) and Multi-Mode (OM1–OM5) | Multi-Mode (OM1/OM2 primarily) and Single-Mode |
|
Typical Insertion Loss
|
0.10–0.25 dB | 0.25–0.40 dB |
|
Polish Types Available
|
UPC (Ultra Physical Contact, Blue) and APC (Angled, Green) | — |
|
Duplex Clip Pitch
|
6.25 mm | — |
|
Polish Type
|
— | PC / UPC (Round metal housing) |
|
Mating Cycles
|
— | 500+ cycles |