What Is a Fiber Optic Adapter?
A fiber optic adapter (also called a coupler or bulkhead) is a passive device used to connect two fiber optic cables, allowing optical signals to pass from one to the other. It uses a precision ceramic alignment sleeve to ensure low insertion loss.
Langzhi Technology offers a full range of adapters, with the SC/APC to SC/APC single-mode adapter being our best-selling model (16,800+ sales).
Common Adapter Types
By Connector Type
- SC Adapter — Most common, 2.5mm ferrule, push-pull lock, widely used in FTTH/GPON
- LC Adapter — 1.25mm ferrule, half the size, for high-density data centers
- FC Adapter — Threaded lock, vibration-resistant, for test equipment
- ST Adapter — Bayonet lock, for multimode networks
By Polish Type
- APC (Green) — 8° angle, RL≥60dB, green color, for GPON/CATV
- UPC (Blue) — Ultra polish, RL≥50dB, blue color, for digital通信
How to Choose
⚠️ Never mix APC and UPC! Always match the adapter polish type to the connector polish type. Check the color code: Green = APC, Blue = UPC.
Also match connector type (SC to SC, LC to LC) and fiber mode (single-mode or multimode).
