Exfo ELS-500 850/1300nM 1310/1550nM Optical Light Source

The Exfo ELS-500 is a quad-wavelength optical light source engineered for loss and continuity verification across multimode and singlemode fiber networks, including FTTx and passive optical network (PON) deployments. Operating at 850 nm and 1300 nm for multimode fiber, and 1310 nm and 1550 nm for singlemode applications, the unit delivers output power of ≥ -5 dBm (singlemode) and ≥ -24 dBm (multimode, 50/125 µm). Two ports accommodate all four wavelengths with automatic wavelength switching, eliminating offset nulling and reducing test error.

The unit operates continuously with 0 minutes warm-up time and stable output within ±0.10 dB typical across its range.

Technical Specifications

• Wavelengths: 850 nm, 1300 nm (multimode); 1310 nm, 1550 nm (singlemode)


• Output Power: ≥ -5 dBm (1310/1550 nm); ≥ -24 dBm multimode (50/125 µm)


• Spectral Width: 850 nm (±25 nm), 1300 nm (+50/-20 nm), 1310 nm (±20 nm), 1550 nm (±20 nm)


• Output Power Stability: ±0.10 dB (typical)


• Modulation: CW, 270 Hz, 1 kHz, 2 kHz


• Tone Generation: 270 Hz, 1 kHz, 2 kHz for fiber identification


• Laser Classification: Class 1M or Class 3R, depending on configuration

Key Features

• Automatic wavelength switching for reduced operator intervention and error elimination


• Dual-port architecture supporting four wavelengths simultaneously


• Data storage capacity of 1000 items with USB PC transfer capability


• Keypad and LCD backlight for operation in low-light field environments


• Rechargeable battery operation with up to 70 hours typical battery life


• Compact dimensions: 189 mm × 78 mm × 37 mm; weight 0.4 kg


• Operating temperature range: -10 °C to 50 °C

Typical Applications

• FTTx network installation and commissioning at ITU-T G.983.3 recommended wavelengths (1310, 1490, 1550 nm)


• Passive optical network (PON) testing and troubleshooting


• Multimode and singlemode fiber loss and continuity verification


• Field maintenance and troubleshooting by technicians

Compatibility & Integration The ELS-500 integrates directly with the Exfo EPM-500 Power Meter, enabling synchronized wavelength switching and automated measurement workflows. Powered via rechargeable batteries with AC adapter charging, the unit supports data export through USB connectivity for analysis and documentation.