Laser Heads

The laser head is the source of the laser beam used in all laser motion and position measurement systems. The primary difference between laser heads is in the velocity, reference frequency and optical output power. Other considerations are size, heat dissipation, and input power requirements. Which laser you choose depends primarily on the application in which it will be used. For example, semiconductor lithography systems typically have faster moving parts (stages), and therefore need higher velocities than machine tool applications.

Laser heads are configured with appropriate optics and system electronics to build a laser interferometer system that meets the unique physical layout and measurement requirements of individual applications. We can help you build a custom position measurement system that improves product quality, increases yields, and facilitates manufacture of precision products.

Choose a laser head from the table below. For characteristics common to all laser heads, see the list below. Please contact us if different velocities, reference frequencies, or beam diameters are required.

All laser heads have the following characteristics:

• Type: Helium-Neon, continuous wave output, two-frequency (Heterodyne)
• Polarizations: f₁, the lower frequency, is horizontal; f₂, the higher frequency, is vertical. The difference between f₁ and f₂ is the reference frequency. See table below.
• Wavelength: 632.99137 nm (nominal, in vacuum) 5517A/B/BL/C/CL/D/DL, 632.99139 nm (nominal, in vacuum) 5517EL/FL/GL
• Wavelength accuracy: ± 0.1 ppm (vacuum, 3 sigma, lifetime). ± 0.02 with factory calibration to MIL-STD 45663
• Wavelength stability: of ± 0.002 ppm 1 hour (typical, vacuum), ± 0.02 ppm lifetime (vacuum)
• Measurement range: 40 meters (130 feet) for the sum of all axes
• Safety classification: Class II laser product conforming to U.S. National Center for Devices and Radiological Health Regulations 21 CFR 1040.10 and 1040.11
• MTBF: > 50,000 hours typical
• Magnetic field strength: <= 5.25 milliGauss at a distance of 4.6 m (15 ft) from any point on the surface of the packaged laser head (due to permanent magnets around the tube, non-operating)
• Heat dissipation: 23W operating, 35W warm-up
• Clearance required for cabling: 12 cm beyond back of unit (5517A), 10.16 cm beyond back of unit (5517B/BL/C/CL/D/DL/EL/FL/GL)
• Warranty: 3 years

Laser head product model numbers ending in "L" (e.g. 5517DL) have the following additional characteristics:

• Venting: to allow forced air cooling to reduce the power dissipated into the application