EXFO ELS-50 Optical Light Source – 1310/1550nm Dual Wavelength, 60-Hour Battery
The EXFO ELS-50 is a professional dual-wavelength optical light source designed for fiber optic insertion loss testing in FTTH, telecom, and CATV networks. Trusted by field technicians worldwide, it delivers ±0.10dB output stability at both 1310nm and 1550nm — the two standard singlemode wavelengths — powered entirely by standard AA batteries for up to 60 hours of continuous operation. No charging, no proprietary packs. Just reliable, repeatable measurements all day in the field.
Pair it with the EXFO EPM-50 Optical Power Meter for a complete, matched insertion loss test set from a single trusted brand.
Key Specifications at a Glance
| Parameter | ELS-50 (Model 23BL) |
|---|---|
| Wavelengths | 1310nm / 1550nm (singlemode) |
| Output Power | ≥ −5 dBm |
| Power Stability | ±0.10 dB |
| Spectral Width | ≥ 5nm |
| Tone Generation | 270Hz / 1kHz / 2kHz |
| Battery Life | 60 hours (standard AA) |
| Connector | Interchangeable: FC, SC, ST, LC |
| Dimensions | 189 × 78 × 37 mm |
| Weight | 400g (0.9 lb) |
| Operating Temp | −10°C to +50°C |
| Warranty | 1 Year |
Why Field Technicians Choose the EXFO ELS-50
- 60-Hour Battery Life on AA Batteries: Over 2.5 days of uninterrupted field testing — no charging infrastructure needed, no proprietary battery packs to replace or carry.
- ±0.10dB Power Stability: Consistent, repeatable output ensures accurate insertion loss measurements across all test conditions and temperatures.
- Dual Wavelength 1310/1550nm: Tests both standard singlemode telecom wavelengths in a single compact instrument — ideal for FTTH, OSP, and enterprise fiber networks.
- 270/1k/2kHz Tone Generation: Identify and trace individual fibers in multi-fiber cables without interrupting live service — up to 60 hours of tone output.
- Interchangeable Connector Adapters: Field-swappable FC, SC, ST, and LC adapters for maximum flexibility across all connector types. FC adapter included.
- Rugged EXFO Platform: Built for demanding outdoor environments; trusted by telecom operators, contractors, and network integrators globally.
- Compact & Lightweight: 400g, 189×78×37mm — fits in a tool bag or jacket pocket for easy field carry.
- Perfect Pair with EXFO EPM-50: Matched form factor, AA battery platform, and EXFO FiberBasix reliability for a complete insertion loss test set.
What Is the EXFO ELS-50 Used For?
The ELS-50 is the light source half of a two-instrument optical loss test set (OLTS). It injects stable optical power into the fiber under test; a calibrated power meter (such as the EXFO EPM-50) at the far end measures received power. The difference — in dB — is the insertion loss of the fiber link. This test is required for:
- FTTH / FTTx network installation and acceptance testing — verifying fiber links meet operator loss budgets before service activation
- Telecom OSP construction and maintenance — testing aerial, underground, and in-building fiber runs
- CATV fiber plant testing — measuring loss in hybrid fiber-coax (HFC) distribution networks
- Enterprise and data center fiber certification — validating structured cabling for 10G/40G/100G applications
- Fiber identification — using 270Hz/1kHz/2kHz tone to trace specific fibers in multi-fiber cables
EXFO ELS-50 vs. Competitors: What Makes It Different?
Most optical light sources in this class use rechargeable lithium batteries with 8–20 hour runtimes, requiring overnight charging between shifts. The EXFO ELS-50 runs 60 hours on standard AA batteries — available anywhere in the world — eliminating charging downtime and proprietary battery costs. Combined with EXFO's proven ±0.10dB stability and the interchangeable connector system, the ELS-50 delivers a lower total cost of ownership for field teams running multi-day projects.
Complete Insertion Loss Test Set: ELS-50 + EPM-50
The ELS-50 is engineered to pair with the EXFO FiberBasix EPM-50 Optical Power Meter. Together they form a complete, matched OLTS:
- ELS-50 injects stable 1310nm or 1550nm optical power into the fiber
- EPM-50 measures received power at the far end and displays insertion loss in dB after referencing
- Both share the same compact form factor, AA battery platform, and EXFO FiberBasix reliability
- Single-brand accountability for calibration, support, and warranty
See our EXFO EPM-50 listing to complete your test set.
Frequently Asked Questions
Q: What is the EXFO ELS-50?
A: The EXFO ELS-50 is a professional dual-wavelength optical light source that outputs stable optical power at 1310nm and 1550nm for fiber optic insertion loss testing. It is part of the EXFO FiberBasix series and is designed to pair with the EXFO EPM-50 power meter.
Q: What power meter is compatible with the EXFO ELS-50?
A: The ELS-50 is designed to pair with the EXFO FiberBasix EPM-50 Optical Power Meter for a complete insertion loss test set. Both instruments share the same compact form factor, AA battery platform, and EXFO FiberBasix reliability.
Q: How long does the battery last on the EXFO ELS-50?
A: The ELS-50 runs on standard AA batteries with 60 hours of continuous operation — over 2.5 days of uninterrupted field testing. This eliminates the need for charging infrastructure and avoids proprietary battery pack costs.
Q: What connector types does the EXFO ELS-50 support?
A: The ELS-50 features interchangeable connector adapters supporting FC, SC, ST, and LC connector types. The FC adapter is included; additional adapters are available separately.
Q: What is tone generation on the ELS-50 and how is it used?
A: The ELS-50 modulates its optical output at 270Hz, 1kHz, or 2kHz. When used with a compatible power meter or fiber identifier, this tone allows technicians to identify and trace specific fibers within a multi-fiber cable without interrupting live service — up to 60 hours of tone output.
Q: Is the EXFO ELS-50 suitable for FTTH testing?
A: Yes. The ELS-50 is widely used for FTTH/FTTx network installation and acceptance testing, verifying that fiber links meet operator loss budgets at both 1310nm and 1550nm before service activation.
Q: What is the output power stability of the EXFO ELS-50?
A: The ELS-50 delivers ±0.10dB power stability, ensuring consistent and repeatable insertion loss measurements across all test conditions and operating temperatures.
Q: What is included in the EXFO ELS-50 package?
A: The package includes the ELS-50 light source main unit, AA batteries, FC connector adapter, quick reference sticker, certificate of compliance, and soft carrying pouch.
Q: What warranty does the EXFO ELS-50 come with?
A: The ELS-50 comes with a 1-year warranty and certificate of compliance. For support or bulk/B2B pricing, contact us at info@splicermarket.com.
Package Contents
- EXFO ELS-50 Light Source Main Unit
- AA Batteries
- FC Connector Adapter
- Quick Reference Sticker
- Certificate of Compliance
- Soft Carrying Pouch