Agilent/Keysight 5517EL

The Agilent/Keysight 5517EL is a helium-neon two-frequency laser head delivering stable 632.99139 nm light for precision dual-frequency interferometry. This continuous-wave source provides wavelength accuracy of ±0.1 ppm (vacuum, 3 sigma, lifetime) with exceptional stability of ±0.002 ppm per hour, meeting demands in metrology, positioning, and calibration systems where high measurement accuracy is critical.

Technical Specifications

• Type: Helium-neon, continuous wave, two-frequency (heterodyne)


• Wavelength: 632.99139 nm (nominal, in vacuum)


• Wavelength Accuracy: ±0.1 ppm (vacuum, 3 sigma, lifetime); ±0.02 ppm with MIL-STD 45663 factory calibration


• Wavelength Stability: ±0.002 ppm per hour (typical, vacuum); ±0.02 ppm lifetime (vacuum)


• Reference Frequency: ≥5.8 MHz


• Classification: Class II Laser Product (21 CFR 1040.10 and 1040.11) Performance


• Output Power: 65–220 µW (minimum 50 µW after 3 years)


• Beam Diameter: 6 mm


• Beam Height: 80.8 ± 1.0 mm


• Maximum Linear Velocity: 1740 mm/s (with linear optics)


• Measurement Range: 40 meters (130 feet) for sum of all axes


• Mean Time Between Failures: >50,000 hours (typical) Electrical Requirements


• Input: +15 V ± 0.3 V @ 2.2 A max; −15 V ± 0.3 V @ 0.03 A max


• Power Supply: Agilent/Keysight 10884B or equivalent


• Heat Dissipation: 23 W operating, 35 W warm-up Physical & Environmental


• Weight: 3.2 kg (7 lb)


• Warm-up Time: 45 minutes (with fan connected to vent body)


• Mounting: M8 × 1.25 tapped holes; kinematic rear-foot mounting recommended for non-aluminum surfaces


• Clearance: 10.16 cm (4 inches) required beyond back of unit for cabling

Key Features

• Two-frequency heterodyne output enables direct velocity and acceleration measurement


• ±0.002 ppm/hour stability supports long-term metrology without frequent recalibration


• Optional MIL-STD 45663 factory calibration reduces wavelength uncertainty to ±0.02 ppm


• >50,000 hour MTBF ensures reliability in production-critical applications


• 40-meter measurement range accommodates large-scale positioning systems

Typical Applications

• Laser interferometry for precision displacement and velocity measurement


• Semiconductor lithography equipment calibration


• Flat panel display manufacturing alignment systems


• Precision metrology and dimensional calibration instruments

Compatibility & Integration Requires Agilent/Keysight 10884B power supply. High-velocity applications may require specialized receivers such as the E1709A. Mounting feet accommodate standard M8 × 1.25 fasteners on aluminum or equivalent surfaces.