How do I choose between LC, SC, and MPO fiber connectors?

Connector choice affects density, cost, and application suitability.

LC (Lucent Connector)

• Small form factor (SFF) push-pull design
• 1.25mm ferrule
• Most common in modern SFP/SFP+
• Duplex clip pairs two fibers
• Standard for 1G/10G/25G single-lane optics

SC (Subscriber Connector)

• Larger 2.5mm ferrule
• Push-pull latching
• Common in older equipment and outdoor plant
• More robust for harsh environments
• Still standard in FTTH/GPON

MPO/MTP (Multi-fiber Push-On)

• Multi-fiber connector (typically 12 or 24 fibers)
• Used in QSFP+ (40G), QSFP28 (100G SR4)
• Enables parallel optics
• Density advantage in data centers

Connector Comparison

Connector Polish Types

• UPC (Ultra Physical Contact): Blue, standard, 0.5 dB return loss
• APC (Angled Physical Contact): Green, 8° angle, better return loss, for high-power/analog
• Never mix UPC and APC — damages ferrules

Selection Guidelines

• New enterprise/DC: LC for singles, MPO for parallel
• Legacy migration: Match existing (usually SC or LC)
• FTTH/PON: SC/APC standard
• Outdoor/harsh: SC for robustness or hardened LC
• High-density: LC or MPO based on speed

Care and Handling

• Always cap unused connectors
• Clean before every mating
• Use inspection scope for critical links
• Never touch the ferrule end-face