# Fiber Type Reference: OS2, OM3, OM4 and OM5 > Source: https://netray.co/tools/fiber-type-reference-os2-om3-om4-om5 > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: Free Tools ## Short answer Searchable table comparing OM1 to OM5 multimode and OS1, OS2 single-mode fiber, with core size, attenuation, bandwidth, color and reach. ## Category industry-templates ## Industry Fiber Optics ## Audience - Fiber optic engineer - Network designer - Procurement buyer ## Tool **Kind:** worksheet **Mode:** reference **Columns:** #### Fiber type **Key:** type **Type:** text #### Mode **Key:** mode **Type:** text #### Core / cladding (um) **Key:** core **Type:** text #### Standard reference **Key:** std **Type:** text #### Max attenuation (dB/km) **Key:** atten **Type:** text #### Modal bandwidth (MHz.km) **Key:** bw **Type:** text #### Typical jacket color **Key:** color **Type:** text #### 10G reach **Key:** reach10 **Type:** text #### 40G SR4 reach **Key:** reach40 **Type:** text #### Notes **Key:** notes **Type:** text **Rows:** **Type:** OM1 **Mode:** Multimode **Core:** 62.5/125 **Std:** ISO/IEC 11801, IEC 60793-2-10 A1b **Atten:** 3.5 at 850 nm, 1.5 at 1300 nm **Bw:** 200 at 850, 500 at 1300 **Color:** Orange **Reach10:** 33 m **Reach40:** Not supported **Notes:** Legacy LED-based installations. Not recommended for new builds. **Type:** OM2 **Mode:** Multimode **Core:** 50/125 **Std:** ISO/IEC 11801, IEC 60793-2-10 A1a.1 **Atten:** 3.5 at 850 nm, 1.5 at 1300 nm **Bw:** 500 at 850, 500 at 1300 **Color:** Orange **Reach10:** 82 m **Reach40:** Not supported **Notes:** Common in older building backbones. **Type:** OM3 **Mode:** Multimode **Core:** 50/125 **Std:** ISO/IEC 11801, IEC 60793-2-10 A1a.2 **Atten:** 3.5 at 850 nm (3.0 in TIA), 1.5 at 1300 nm **Bw:** 1500 overfilled, 2000 EMB at 850 **Color:** Aqua **Reach10:** 300 m **Reach40:** 100 m **Notes:** Laser-optimized for VCSEL sources. **Type:** OM4 **Mode:** Multimode **Core:** 50/125 **Std:** ISO/IEC 11801, IEC 60793-2-10 A1a.3 **Atten:** 3.5 at 850 nm (3.0 in TIA), 1.5 at 1300 nm **Bw:** 3500 overfilled, 4700 EMB at 850 **Color:** Aqua (some vendors use violet) **Reach10:** 400 m **Reach40:** 150 m **Notes:** Common for data center backbones and short reach links. **Type:** OM5 **Mode:** Multimode **Core:** 50/125 **Std:** ISO/IEC 11801, IEC 60793-2-10 A1a.4, TIA-492AAAE **Atten:** 3.0 at 850 nm, 1.5 at 1300 nm **Bw:** 3500 at 850 overfilled, 1850 at 953; EMB 4700 and 2470 **Color:** Lime green **Reach10:** 400 m **Reach40:** 150 m **Notes:** Wideband multimode designed for short wavelength division multiplexing (SWDM). Backward compatible with OM4. **Type:** OS1 **Mode:** Single-mode **Core:** 9/125 **Std:** ISO/IEC 11801, ITU-T G.652 **Atten:** 1.0 at 1310 and 1550 nm **Bw:** Not applicable **Color:** Yellow **Reach10:** 10 km (10GBASE-LR) **Reach40:** Not applicable **Notes:** Tight-buffered indoor cable. Higher attenuation than OS2. **Type:** OS2 **Mode:** Single-mode **Core:** 9/125 **Std:** ISO/IEC 11801, ITU-T G.652.D **Atten:** 0.4 at 1310 and 1550 nm **Bw:** Not applicable **Color:** Yellow **Reach10:** 10 km (10GBASE-LR), 40 km (ER) **Reach40:** Not applicable **Notes:** Loose-tube indoor/outdoor and campus or metro links. Typical installed loss is lower than the maximum. **Type:** G.652.D **Mode:** Single-mode **Core:** 9/125 **Std:** ITU-T G.652 **Atten:** 0.4 at 1310 and 1550 nm **Bw:** Not applicable **Color:** Yellow **Reach10:** Depends on transceiver **Reach40:** Not applicable **Notes:** Standard single-mode fiber with low water peak. Basis of most OS2 cable. **Type:** G.657.A1 **Mode:** Single-mode **Core:** 9/125 **Std:** ITU-T G.657 **Atten:** Similar to G.652.D **Bw:** Not applicable **Color:** Yellow **Reach10:** Depends on transceiver **Reach40:** Not applicable **Notes:** Bend-insensitive, compatible with G.652.D. Minimum bend radius 10 mm. **Type:** G.657.A2 **Mode:** Single-mode **Core:** 9/125 **Std:** ITU-T G.657 **Atten:** Similar to G.652.D **Bw:** Not applicable **Color:** Yellow **Reach10:** Depends on transceiver **Reach40:** Not applicable **Notes:** Bend-insensitive, compatible with G.652.D. Minimum bend radius 7.5 mm. **Type:** G.657.B3 **Mode:** Single-mode **Core:** 9/125 **Std:** ITU-T G.657 **Atten:** Similar to G.652.D **Bw:** Not applicable **Color:** Yellow **Reach10:** Depends on transceiver **Reach40:** Not applicable **Notes:** Strong bend resistance for in-building and drop cables. Minimum bend radius 5 mm. **Type:** G.655 **Mode:** Single-mode **Core:** About 9/125 **Std:** ITU-T G.655 **Atten:** About 0.35 at 1550 nm **Bw:** Not applicable **Color:** Yellow **Reach10:** Long-haul DWDM **Reach40:** Not applicable **Notes:** Non-zero dispersion shifted fiber for DWDM at 1550 nm. **Type:** G.654 **Mode:** Single-mode **Core:** 9/125 class **Std:** ITU-T G.654 **Atten:** About 0.17 to 0.20 at 1550 nm **Bw:** Not applicable **Color:** Yellow **Reach10:** Subsea and ultra-long haul **Reach40:** Not applicable **Notes:** Cut-off shifted fiber with a large effective area and very low loss at 1550 nm. **Notes:** Values are typical standards-based figures for planning. Always confirm limits against the cable datasheet and the specific standard edition. Reach shown is for the stated Ethernet PHY and depends on the transceiver. ## Content **Intro:** Choosing between OM3, OM4, OM5 and OS2 comes down to distance, data rate and cost. This table lists the core size, loss, bandwidth, usual jacket color and reach so you can compare fiber types in seconds. **Sections:** #### How to use the table **Body:** Search by type, standard or jacket color to filter the rows. Multimode fiber (OM1 to OM5) has a 50 or 62.5 micron core and is used with short wavelength VCSEL transceivers for runs inside buildings and data centers. Single-mode fiber (OS1 and OS2) has a 9 micron core, uses 1310 or 1550 nm lasers, and covers kilometers. Use the reach columns to match a fiber type to an Ethernet PHY, then check cost and transceiver availability before you decide. **Bullets:** - Under 300 m inside a building: OM3 or OM4 is usually enough - 400 m and above or campus links: OS2 single-mode - SWDM transceivers: OM5 to get the benefit of wideband multimode - New builds: skip OM1 and OM2 unless you must match existing plant #### How to read the columns **Body:** Attenuation is the maximum loss per kilometer used for acceptance testing, though installed cable is often better. Modal bandwidth in MHz.km limits the distance for multimode at high rates. Overfilled launch values apply to LED sources, while effective modal bandwidth (EMB) applies to laser launch and is what matters for OM3, OM4 and OM5. Jacket colors are conventions from TIA-598 and not a guarantee, so confirm the type from the cable print line or datasheet before you connect anything. #### OM4 versus OM5 **Body:** OM4 and OM5 have the same core and the same performance at 850 nm. OM5 adds specified bandwidth at 953 nm so that SWDM transceivers can run four wavelengths over a single pair of fibers, cutting fiber count for 40G and 100G links. If you use only standard 850 nm optics, OM5 gives no distance advantage over OM4. Many projects still choose OM5 for future flexibility, but OM4 is often cheaper and fully adequate. #### Common mistakes **Body:** Mixing multimode core sizes is a frequent error: connecting 62.5 micron to 50 micron can add several dB of loss in one direction. Another is assuming all yellow cable is OS2, since some indoor tight-buffered cable is OS1 with higher loss. Also check the reach assumption: the 10G, 40G and 100G distances depend on the transceiver type and connector count, and long links may need a loss budget calculation as well. **Cta:** If you manage fiber and cable inventory as items in an ERP, we can help structure the attributes so types and specs are searchable. Reach out if you want to talk about it. **Faq:** #### What is the difference between OS1 and OS2? **Answer:** Both are 9/125 single-mode fibers. OS1 is usually tight-buffered indoor cable with up to 1.0 dB/km loss, while OS2 is loose-tube cable with up to 0.4 dB/km. OS2 is preferred for new designs and longer runs. #### Is OM5 backward compatible with OM4? **Answer:** Yes. OM5 has the same 50/125 core and works with standard 850 nm transceivers like OM4. Its extra specification at 953 nm only matters when you use SWDM optics that run multiple wavelengths. #### What color is each fiber type? **Answer:** Commonly OM1 and OM2 are orange, OM3 and OM4 are aqua, OM5 is lime green and single-mode is yellow. These are conventions, not guarantees, so verify the type from the cable marking or datasheet. #### Can I mix OM3 and OM4 in one link? **Answer:** You can physically, but the link performance is limited by the weaker fiber, and the reach must be calculated for the lower grade. Keep one fiber grade per channel when possible to avoid surprises. ## Search terms OS2 OM3 OM4 OM5 difference, fiber types reference, multimode fiber types chart, OM4 vs OM5, OS1 vs OS2, fiber optic cable color code, multimode fiber bandwidth table, single mode vs multimode fiber --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json