StarTech SMLCSC-OS2-3M LC to SC OS2 Single Mode Fiber Patch Cable

Overview

The StarTech SMLCSC-OS2-3M is a 3-meter (9.8 ft) LC duplex to SC duplex OS2 single mode fiber patch cable built for high-density data center interconnects, backbone runs between IDF and MDF closets, and any application where you need a clean, low-loss link at speeds up to 100Gbps. The 9/125 micron OS2 fiber core and UPC-polished connectors deliver the kind of signal integrity that matters when you're running 10G, 25G, 40G, or 100G transceivers — not just today's hardware, but whatever gets installed during the next refresh cycle.

The LSZH (Low Smoke Zero Halogen) jacket keeps this cable compliant with building and fire codes in enclosed spaces like server rooms, plenum corridors, and equipment closets where jacket material is a real concern during an emergency — not just a checkbox on a spec sheet. This cable is also commonly searched as SMLCSC OS2 3M.

Key Features

• OS2 9/125 Single Mode Fiber: OS2 is optimized for long-distance, low-attenuation transmission. Unlike OM3/OM4 multimode, OS2 supports runs of several kilometers — useful if this patch connects to a longer backbone segment where signal budget matters. For short in-rack or cross-patch-panel runs, the headroom it provides means zero concern about margin.
• 100Gbps Maximum Data Rate: This cable handles 10GbE, 25GbE, 40GbE, and 100GbE without any requalification. Future-proofing your fiber layer is far cheaper than re-pulling cables after a switch upgrade, and this cable won't be the limiting factor.
• 0.3dB Insertion Loss: Every connection in a fiber link eats into your optical power budget. At 0.3dB insertion loss per connector pair, this cable keeps that budget well within margin for virtually any transceiver combination running over OS2. Lower insertion loss also translates to cleaner BER (bit error rate) performance at distance.
• 55dB Return Loss: High return loss means very little light reflects back toward the transmitter — important for laser-based transceivers that are sensitive to back-reflection. At 55dB, this cable is compatible with high-speed coherent and direct-detect optics without additional isolation hardware.
• 1260nm to 1625nm Wavelength Range: This covers all standard single mode transmission windows — O, E, S, C, and L bands — so it's compatible with CWDM, DWDM, and standard gray optics. You're not locked into a narrow wavelength range, which matters if your environment mixes vendor transceivers.
• LSZH (Low Smoke Zero Halogen) Jacket: In a fire scenario, standard PVC jackets release toxic halogen gases. The LSZH jacket on this cable limits smoke and toxic emissions — a requirement in many European installations and increasingly specified in US commercial buildings and data centers. Verify your local code before specifying PVC alternatives in enclosed spaces.
• LC Duplex to SC Duplex Connectors: LC is the dominant connector in modern switches, transceivers, and patch panels. SC remains common on older equipment, legacy infrastructure, and some telecom gear. This cable bridges those two worlds without an adapter — adapters introduce additional insertion loss and a mechanical failure point.
• 2mm Cable OD: Slim 2mm duplex construction keeps cable management clean in high-density environments. In a fully loaded patch panel bay, fat cables are a real problem — 2mm stays manageable even at high counts.
• Operating Temperature -20°C to 60°C: Rated for both cold storage environments and warm equipment closets. The -20°C floor also means it survives unheated spaces during installation in winter months without brittleness risk.
• Lifetime Warranty: StarTech backs this cable with a lifetime warranty, which is relevant for any permanent infrastructure installation — you won't be re-sourcing a replacement in three years when the original purchase is long gone.

Integration and Compatibility

The SMLCSC-OS2-3M works with any LC duplex SFP, SFP+, SFP28, QSFP breakout, or similar transceiver on one end, and SC duplex ports on the other. Common use cases include patching from a modern LC-based switch or media converter to an SC-based fiber distribution panel, legacy telephony equipment, or older campus fiber runs. The UPC polish on both connectors is standard for data applications; APC-polished equipment (typically green connectors) requires an APC-to-UPC adapter and will introduce additional return loss — confirm your termination types before ordering.

This cable is appropriate for single mode fiber optic cables applications inside structured cabling plants, cross-connects in MDF/IDF closets, and SFP-based network switches that require patching to legacy SC infrastructure. For OS2 deployments involving longer backbone segments, review your fiber optic transceivers optical power budget against your total link loss — a single 3m patch is rarely the constraint, but documenting the full link budget is good practice.

If your environment requires OM3 or OM4 multimode instead of OS2 single mode, or if you need a different length or connector combination, the broader StarTech fiber cable lineup covers most combinations. Confirm transceiver wavelength compatibility (850nm for multimode VCSELs vs. 1310nm/1550nm for single mode lasers) before swapping fiber types.

Frequently Asked Questions

Q: What is the maximum data rate supported by the SMLCSC-OS2-3M?

A: The SMLCSC-OS2-3M supports a maximum data transfer rate of 100Gbps, making it compatible with 10GbE, 25GbE, 40GbE, and 100GbE applications over OS2 single mode fiber.

Q: What connector types are on each end of this cable?

A: One end terminates in an LC duplex connector; the other terminates in an SC duplex connector. Both connectors use a UPC (Ultra Physical Contact) polish. APC-polished ports (typically identified by green connectors or housings) are not directly compatible without an adapter.

Q: Is the SMLCSC-OS2-3M safe to use in enclosed spaces or plenum environments?

A: The cable jacket is rated LSZH (Low Smoke Zero Halogen), which limits toxic smoke emissions in the event of a fire. This satisfies requirements in many enclosed commercial and data center environments. Confirm the specific fire rating required by your local building code before installation.

Q: What is the warranty on the SMLCSC-OS2-3M?

A: StarTech provides a lifetime warranty on the SMLCSC-OS2-3M.

Q: Can I use this cable with multimode fiber transceivers?

A: No. OS2 single mode fiber requires single mode transceivers operating at 1310nm or 1550nm wavelengths. Multimode transceivers (typically 850nm VCSELs for OM3/OM4) are not compatible with OS2 fiber. Using mismatched fiber types will result in unacceptable signal loss.

Q: What is the insertion loss specification for the SMLCSC-OS2-3M?

A: Insertion loss is rated at 0.3dB, and return loss is rated at 55dB. These values are consistent with low-loss UPC connector performance and are compatible with the optical power budgets of standard single mode transceivers.

Marty Allison

The spec I keep coming back to on the SMLCSC-OS2-3M is the 55dB return loss. That's not a number most people scrutinize on a short patch cable, but when you're running 25G or 100G direct-detect optics — particularly in a dense patch environment where connectors get handled repeatedly — back-reflection is a real failure mode. At 55dB you have substantial margin against the sensitivity thresholds of typical SFP28 and QSFP28 transceivers, which usually spec 27–30dB minimum return loss tolerance.

Technical Highlights:

• 0.3dB Insertion Loss: Tight enough that even if you're stacking two patches through an adapter panel, your total connector loss stays well within the 1–2dB budget most OS2 link calculations allocate to connectors. Clean end-face performance means fewer cleaning cycles and lower maintenance overhead in a dense closet.
• 1260nm–1625nm Wavelength Coverage: This range covers every standard single mode transmission window. If your environment runs CWDM or DWDM alongside conventional gray optics, you're not carrying a separate cable inventory — this cable handles all of it without wavelength-specific restrictions.
• LSZH Jacket, 2mm OD: LSZH is the right call for any enclosed equipment room. The 2mm slim form factor matters when you're managing 48-port patch panels — fat cables in high-density runs create airflow problems and make re-patching a two-person job. At 32 grams for a 3-meter run, it routes easily without stressing connector ferrules.

Deployment Considerations:

• Confirm UPC vs. APC on both ends before installing. If the SC port on your target device uses APC polish (green body, angled ferrule), you'll need an APC adapter — direct UPC-to-APC mating increases return loss significantly and degrades link performance on sensitive optics.
• Operating temperature is rated down to -20°C, which covers unheated telecom closets and outdoor-rated enclosures in most climates. However, the humidity spec (40–70%) means this cable is not appropriate for high-humidity environments like outdoor-exposed conduit pulls without additional protection.

This cable is well-positioned for MDF-to-patch-panel cross-connects in enterprise data centers and commercial building structured cabling plants where modern LC-based switching infrastructure needs to interface with existing SC-terminated fiber distribution frames — a scenario that comes up constantly during phased infrastructure upgrades.