The Keysight 5517CL is a helium-neon laser head engineered for precision displacement and velocity measurement in VME and PC-based laser interferometer systems. This two-frequency continuous laser delivers wavelength stability and accuracy suitable for semiconductor lithography, flat panel manufacturing, and precision metrology applications requiring strict thermal control.
Technical Specifications
Laser Output
• Type: Helium-neon, continuous, two-frequency
• Wavelength (nominal vacuum): 632.99137 nm
• Wavelength accuracy (3 sigma, lifetime): 0.1 ppm
• Wavelength accuracy (optional A6J): 0.02 ppm
• Wavelength stability (1 hour typical): 0.002 ppm
• Wavelength stability (lifetime typical): 0.02 ppm
• Maximum beam power output: 180 microwatts
• Beam diameter standard: 6 mm (3 mm or 9 mm options available)
• Beam height: 80.8 ± 1.0 mm
• Split beam orthogonality (Option 301): 0.7 degrees
Performance Parameters
• Reference frequency: 2.4 MHz to 3.0 MHz
• Maximum velocity (linear optics): 700 m/s
• Maximum velocity (plane mirror optics): 350 m/s
• Mean time between failures: > 50,000 hours (typical)
• Warm-up time: 45 minutes (with vented cover fan and exhaust)
Physical & Operational
• Dimensions: 359 × 129 × 132 mm
• Weight: 3.2 kg
• Power supply: +15 V (±0.3 V at 2.2 A maximum), −15 V (±0.3 V at 0.02 A maximum)
• Enclosure: IP10 per IEC 529
• Cabling clearance: 10.16 cm beyond rear panel
• Airflow requirement: 4 m/s minimum through 50 mm diameter duct
• Laser classification: Class II per 21 CFR 1040.10 and 1040.11
– Key Features
• 0.1 ppm wavelength accuracy over lifetime ensures traceable measurements
• Selectable beam diameters (3, 6, or 9 mm) for system optimization
• Two-frequency heterodyne architecture enables bidirectional displacement sensing
• Compact form factor: 3.2 kg with integrated beam path
• Extended MTBF rating supports 24/7 production environments
– Typical Applications
• Semiconductor lithography alignment and overlay measurement
• Flat panel display manufacturing process control
• Precision machine tool calibration and verification
• High-speed linear stage velocity profiling
• Laser interferometer reference source
– Compatibility & Integration
The 5517CL integrates with Keysight VME and PC-based laser interferometer systems, pairing with dedicated electronics modules and optical heads for complete measurement systems. Direct compatibility with Keysight interferometer optics and signal conditioning electronics is required for operation.


















