1. General Information

• Part Number: 8070-0102-01 (often 8070-0102-01X)

• Model: ZMI 7702

• Manufacturer: ZYGO (Ametek)

• Type: Heterodyne HeNe laser head, dual-frequency, linearly polarized

• Application: Semiconductor lithography, ultra-precision stage metrology, interferometryZYGO

• Compatible Electronics: ZMI-501A, ZMI-2400/4000; Nikon NSR-S620D scannersZYGO

2. Optical Characteristics

• Laser Medium: Helium–Neon (HeNe), continuous wave (CW)

• Polarization: Two orthogonal linear polarizations (F1/F2)

• Vacuum Wavelengths:

  • F1 (vertical): 632.991501 nm

  • F2 (horizontal): 632.991528 nm

• Frequency Difference (Split): 20 MHz ± 1600 Hz (AOM shift)

• Output Power:

  • Minimum: > 400 µW

  • Typical (after warm-up): > 625 µW

• Beam Diameter: 3 mm or 6 mm (model-dependent)

• Beam Pointing Stability: < 0.5 arcsec/°C

• Wavelength Stability:

  • 1 hour: 0.005 ppm (2 ppb, 3σ)

  • 24 hours: 0.01 ppm

• Wavelength Lifetime Accuracy: ±0.1 ppm

3. Electrical & Power

• Supply Voltage:

  • +15 VDC ±0.5 V @ 2.1 A

  • −15 VDC ±0.5 V @ 1.2 A

• Max Power Dissipation:

  • Operation: 39 W

  • Warm-up: 50 W

4. Mechanical & Physical

• Weight: 5.5 kg

• Construction: Aluminum casting; Ultem 2400 mounting feet

• Mounting: Narrow or wide base (option dependent)

• Nominal Cable Clearance: 135 mm

5. Timing & Warm‑up

• Laser Output Onset: < 10 s typical; ≤ 70 s max

• Wavelength Stabilization Time: < 10 min typical

6. Environmental

• Operating Temperature: 10 °C to 30 °C

• Storage Temperature: −40 °C to +70 °C

• Relative Humidity: 20%–80% RH, non‑condensing

• Cooling: Air‑cooled

7. Laser Safety

• Classification: Class IIIa

• Compliance: NCDRH / IEC 60825

8. Key Features

• High‑stability 20 MHz heterodyne output for multi‑axis interferometry

• Low drift: 2 ppb frequency stability (1 hour)

• Dual‑axis compatibility with ZMI‑501A and Nikon litho systemsZYGO

• Suitable for long‑term, continuous factory operation