Product Details

The ZYGO 7701 is a discontinued two-frequency He-Ne heterodyne laser head, the matched optical source for ZMI-2001 and ZMI-2002 VME measurement boards, widely used in legacy semiconductor displacement metrology systems. It outputs 632.8nm stable laser with two orthogonal linear polarization frequencies, fixed frequency difference at 20MHz ±1600Hz, which provides the reference optical signal required for heterodyne interferometer displacement calculation.

This laser head supports optional beam diameters of 3mm and 6mm. The 6mm beam version supports a maximum measurement distance up to 25 meters, while the 3mm version is suitable for short stroke optical layout within 2 meters. The output optical power is above 550μW, wavelength long-term accuracy reaches ±0.1ppm, with excellent frequency stability for long-time continuous measurement. The supply voltage is ±15VDC, with preheat time more than 7 minutes before stable metrology operation. It can be connected with optical fiber or free-space optical path to feed interferometer optics, then the return optical signal goes into ZMI-2001 / ZMI-2002 VME processing boards for position decoding. Multiple 7701 laser heads can be configured in one chassis for multi-axis stage systems.

It integrates internal optical isolator and temperature stabilization structure to suppress frequency drift caused by ambient temperature fluctuation. The front panel has power indicator and laser status LED, convenient for routine health check. Users need to match the laser head with corresponding ZMI measurement board, optical interferometer and retroreflector, and verify optical power and frequency difference before installation. The onboard EMC shielding design reduces interference from servo drives in cleanroom environments. The mechanical housing adopts vibration damping structure, suitable for wafer positioning stages, optical alignment benches and ultra-precision machine tools. This legacy ZYGO 7701 laser head is mainly supplied as spare replacement parts for existing ZMI metrology systems. Users need to confirm optical power and frequency consistency when replacing old units. A conformal coated version is optional for high humidity and dusty industrial sites. This laser head is widely used in old laser interferometer system renovation and nanometer motion feedback projects.

This two-frequency He-Ne laser head adopts standalone compact housing structure. It requires ±15VDC power supply. LED indicators display power and laser lock status for convenient on-site inspection. The operating temperature range is 18°C to 25°C for optimal metrology performance, storage temperature ranges from -40°C to +85°C, relative humidity 5% to 50% non-condensing. It complies with industrial shock, vibration and EMC standards and has CE certifications. It supports optical path calibration backup for fast recovery after hardware replacement.

This ZYGO 7701 laser head is widely applied in high-precision laser interferometer measurement systems. It provides stable two-frequency laser source for ZMI series measurement boards. As a reliable spare part for ZYGO legacy metrology systems, the ZYGO 7701 retains original heterodyne frequency characteristics and optical compatibility, helping customers reduce maintenance cost of legacy ultra-precision measurement equipment.