Description

1. Product Overview

The Keysight 5517C (OPT 003, A6J) is a high-precision dual-frequency He-Ne laser head, serving as the core light source unit for laser interferometer precision displacement measurement systems. It is designed for nanometer-level positioning inspection in high-speed motion applications. OPT 003 denotes the 3mm narrow beam output configuration, while A6J is a factory high-precision calibration option. This laser head emits a stable dual-frequency laser at a wavelength of 632.991354nm. Based on the Zeeman splitting heterodyne detection principle, it delivers ultra-high-precision measurement of geometric quantities including displacement, velocity, angle and straightness. With a reference frequency difference of 2.4~3.0MHz, it supports a maximum linear measurement speed of 696mm/s. It is widely applied in semiconductor lithography, flat-panel display manufacturing, coordinate precision metrology, machine tool accuracy calibration, optical laboratory testing and other fields. It can be matched with interferometer systems such as the 5501A, 5527A and 5572A to build automated measurement platforms, and also acts as an original spare part for replacement and upgrade of legacy precision inspection equipment.

2. Hardware Structure and Composition

2.1 Dual-Frequency He-Ne Laser Resonance Emission Unit

It incorporates a sealed He-Ne laser resonant cavity, which adopts Zeeman magnetic splitting technology to generate two orthogonally polarized laser beams with frequency difference, enabling long-term stable wavelength output. Equipped with a 3mm narrow-beam optical collimating module under OPT 003 configuration, it is more suitable for optical layout in confined spaces and long-distance transmission compared with the standard 6mm beam. It effectively reduces beam diffraction loss and improves the signal-to-noise ratio during long-range measurement. The A6J calibration option undergoes factory traceable calibration in accordance with MIL-STD 45662, optimizing the vacuum wavelength accuracy to ±0.02ppm to meet statutory calibration and traceability requirements for metrology-grade equipment. An integrated constant-temperature control loop inside the resonant cavity suppresses wavelength drift caused by ambient temperature variation and ensures data consistency during long-term continuous measurement. The typical mean time between failures (MTBF) of the whole unit exceeds 50,000 hours.

2.2 Power Drive and Voltage Stabilization Protection Unit

It adopts a bipolar DC power supply architecture accepting two regulated input voltages of +15V and -15V, with built-in multi-level hardware protection circuits against overvoltage, undervoltage, reverse connection and surge. The power drive module is equipped with a high-precision constant-current control chip to stabilize the operating current of the laser tube and avoid output power fluctuation induced by voltage variation. An on-board real-time temperature acquisition circuit monitors the operating temperature of the resonant cavity and power devices. It latches fault status under abnormal conditions and sends fault alarm signals to the upper acquisition system to prevent overheating, aging and damage of the laser source.

2.3 Polarized Optical Path and Beam Positioning Unit

The two laser beams are output as horizontally and vertically orthogonally polarized light respectively, with a nominal beam height of 79.5±1.0mm. Precise optical calibration is completed at the factory to guarantee that beam parallelism and polarization degree meet the matching requirements of interferometric receiving modules. Standard mounting reference planes are reserved on the base, together with two types of threaded mounting holes (M6 and 1/4-20), allowing direct fixation on optical platforms, precision translation stages and equipment racks to ensure repeat positioning accuracy during multi-axis optical path setup.

2.4 Enclosure Structure, Heat Dissipation and Mounting Unit

The whole device adopts a die-cast aluminum alloy sealed enclosure with a thermal expansion coefficient matching that of aluminum optical platforms, minimizing optical path offset caused by thermal deformation. Natural convection cooling is adopted, and the large-area heat dissipation structure on the base quickly conducts heat generated by the resonant cavity, requiring sufficient ventilation space around the unit. Detachable mounting feet are fitted on the base for foot-mounted installation; alternatively, the feet can be removed for flush mounting via counterbore threaded holes on the bottom. It is compatible with various installation layouts in laboratories and automated production lines, and directly fits the mounting bases of all optional configurations of the 5517C series for on-site replacement installation.

3. Technical Specifications

3.1 Optical and Electrical Specifications

Laser Type: Continuous-wave Zeeman dual-frequency He-Ne laser, Class II laser product
Nominal Vacuum Wavelength: 632.991354nm
Wavelength Accuracy: Standard ±0.1ppm; A6J calibration option ±0.02ppm (traceable calibration to MIL-STD 45662)
Wavelength Stability: Typical ±0.002ppm over 1 hour; typical ±0.02ppm over service life
Reference Frequency Difference: 2.4~3.0MHz
Beam Specification: OPT 003, beam diameter 3mm, beam height 79.5±1.0mm
Output Power: Minimum 180μW, Maximum 1mW
Maximum Linear Measurement Speed: 696mm/s
Power Supply: +15V±0.3V (Max. 3.0A), -15V±0.3V (Max. 0.3A)
Warm-up Stabilization Time: 90 minutes

3.2 Environmental Specifications

Operating Temperature: 20℃±2℃ (recommended for high-precision metrology), allowable range 15℃~30℃; Storage & Transportation Temperature: -20℃~+60℃
Relative Humidity: 20%~80% RH, non-condensing, free of corrosive gas and dust
Vibration Resistance: Complies with IEC vibration and shock standards for transportation; continuous vibration and impact shall be avoided during operation
EMC Compliance: Meets industrial EMC standards, resisting electrostatic discharge and electrical fast transient interference

3.3 Mechanical Specifications

Mounting Method: Foot-mounted / bottom threaded flush mounting, M6 and 1/4-20 UNC mounting holes
Net Weight: 3.4kg
Enclosure Material: Die-cast sealed aluminum alloy
Standard Options: OPT 003 (3mm narrow beam), A6J high-precision metrology-grade wavelength calibration
Compatible Systems: Keysight 5501A, 5527A, 5572A laser interferometer measurement systems, VME/PC architecture precision positioning measurement and control systems

4. Product Functions and Features

OPT 003 Narrow Beam Design for Confined Optical Paths and Long-Distance Measurement

The 3mm small-diameter collimated beam features lower diffraction and less energy attenuation during long-distance transmission, suitable for compact equipment cavities and densely arranged multi-axis optical layouts. Compared with the standard 6mm beam, it greatly reduces the risk of optical path obstruction and improves the stability of interferometric measurement in compact automated equipment.

A6J Traceable Calibration for Metrology Compliance and Ultra-High Precision Testing

Calibrated in compliance with military standards, it delivers significantly improved wavelength measurement accuracy with legally traceable test data. It is applicable to scenarios with strict error control requirements, including third-party accuracy verification, standard value transfer in laboratories and positioning precision inspection of high-end semiconductor equipment, with compliant calibration reports available for measurement results.

Dual-Frequency Heterodyne Interferometry Enables High-Precision Dynamic Displacement Measurement at High Speed

With dual-frequency laser at a frequency difference of 2.4~3.0MHz, it supports real-time displacement acquisition for moving targets up to nearly 700mm/s. No frame loss or speed measurement distortion occurs during dynamic positioning error inspection of high-speed lithography machines and panel coating equipment, balancing nanometer-level static precision and stable high-speed dynamic measurement performance.

Constant-Temperature Sealed Resonant Cavity Delivers Excellent Long-Term Continuous Operation Stability

A closed-loop temperature control loop suppresses the influence of ambient temperature drift on laser wavelength and output power, satisfying the demand for 7×24-hour non-stop on-line precision inspection on production lines. It greatly reduces the frequency of production line shutdown for optical path recalibration and improves the inspection efficiency of automated manufacturing lines.

Standardized Mechanical Mounting and Backward Compatibility Simplify Equipment Retrofit and Replacement

Uniform mounting references, beam height and electrical interfaces allow direct replacement of 5517C laser heads with different beam specifications within the same series. Minor modifications to the original optical layout and power wiring are required, and system reconstruction can be rapidly completed with factory calibration data, shortening the commissioning cycle for legacy equipment upgrades.

Industrial-Grade Safety Protection Adaptable to Laboratory and Cleanroom Operating Conditions

Class II laser safety rating avoids eye radiation injury under normal operation. The dustproof sealed aluminum alloy enclosure fits clean workshops in the semiconductor and display industries. Built-in multi-level electrical protection withstands minor on-site power fluctuation and electrostatic interference, ensuring long-term reliable operation of the precision optical light source.

5. Applicable Working Conditions and Application Scenarios

Laser interferometric calibration and inspection of X/Y/Z three-axis positioning accuracy, repeat positioning error and straightness for semiconductor lithography equipment and wafer packaging equipment.
On-line calibration of dynamic displacement and speed accuracy for high-speed moving platforms in coating, cutting and handling processes of LCD and OLED panel production lines.
Traceability calibration of length standard instruments such as coordinate measuring machines, precision machine tools and linear encoders in metrology institutes and third-party testing laboratories (the A6J calibration option meets metrology compliance requirements).
Precision measurement of nanometer displacement, angle and pitch deviation for optical precision machining, high-precision translation stages and fiber coupling equipment.
Spare part replacement for legacy Agilent/Keysight 5517 series laser interferometer systems and upgrade projects for compact optical measurement equipment.

Keysight 5517C OPT 003 A6J Dual-wavelength helium-neon laser head