Angle deflection model based on heterodyne interferometry measurement

The ultra-precision positioning technology plays a crucial role in the field of high-precision manufacturing, being widely applied in advanced technologies such as photolithography and nano-manufacturing. Existing ultra-precision positioning techniques include laser interferometers and grating interferometers, among which heterodyne frequency interference technology has become a focal point of research due to its higher precision and good adaptability to modern precision measurement requirements. However, despite the immense potential exhibited by heterodyne interference technology in high-precision measurements, the lack of clarity regarding its angular deviation model has been a key factor limiting its widespread application. Angular deviation not only affects the stability of interference signals but may also lead to increased measurement errors, while existing technologies are unable to provide targeted corrections for this error. Therefore, an in-depth study of the angular deviation model in heterodyne interference is significant for enhancing both the measurement accuracy and stability of interferometers. This paper establishes a comprehensive model addressing the impact of angular deviation based on fundamental principles of heterodyne interference. Additionally, it explores how a new variable—aperture—affects interference signals and analyzes how variations in aperture size influence signal amplitude under conditions of angular deviation. Through experimental validation, we confirm specific patterns regarding how different aperture sizes affect amplitude values within heterodyne interference signals. This research provides theoretical foundations and technical support for installation, calibration, and practical applications involving heterodyne interferometers.