Dual Wavelength Triangulation

Measurement Mechanism

By projecting two light beams with distinct spectral peaks onto a target, the sensor captures the reflected rays from different angles. This dual wavelength triangulation calculates the spatial position of the target surface by analyzing the geometric intersection of the returned light beams. The secondary wavelength provides a reference that resolves phase ambiguities and permits the measurement of step heights that exceed the limits of single wavelength systems.

This dual beam approach enables stable monitoring of complex microstructures during manufacturing.

Calibration Step

Sensors must undergo thorough calibration to align the optical axes of both light sources before beginning high speed inspection runs. Inaccuracies in sensor calibration introduce measurement errors that distort the calculated surface profile and lead to false product rejections. Engineers perform these checks using certified reference standards to determine the scaling factors for each wavelength.

Regular calibration ensures the measurement system remains accurate across varying ambient temperatures.

Integration Penalty

Acquiring and configuring the dual light sources and specialized sensor optics increases the initial setup expenses of the inspection line. When a factory deploys dual wavelength triangulation prematurely, the difficulty of maintaining optical alignment in a high vibration production environment can lead to frequent downtime. This maintenance demand offsets the high resolution advantages if the assembly environment is not carefully controlled.

Isolating the sensor from mechanical vibrations protects the stability of the optical measurement.