Optical Measurement Techniques for 3D Surface Profiling

Optical measurement techniques for three-dimensional surface profiling encompass a range of non-contact, non-destructive methods that exploit the interaction of light with a target to reconstruct its geometry with high spatial resolution. Central approaches include interferometric methods, which use coherent light interference to detect sub-nanometre surface deviations, and structured-light techniques, notably fringe projection profilometry, which project known patterns onto an object and analyse distortions to infer depth. Recent innovations address classical challenges such as specular reflections, dynamic scenes and the need for rapid acquisition. Integration of physics-informed and generative deep-learning models has enabled single-shot and asynchronous measurements, reducing reliance on environmental stability and projector–camera synchronisation. Polarisation-based structured light further extends capability to highly reflective or semi-transparent materials by encoding depth and material properties simultaneously. These advances find application in precision manufacturing, semiconductor inspection, cultural heritage documentation and biomedical diagnostics, where accurate, fast and robust surface mapping is essential for quality control, defect detection and functional analysis.

Research from Nature Portfolio

Recent studies have introduced a polarisation structured-light depth sensor designed to overcome errors caused by reflective surfaces. By employing high-contrast-grating vertical-cavity surface-emitting lasers with orthogonal polarisation states, the system decouples specular reflections from true surface returns, enabling accurate depth reconstruction even behind reflective layers. Performance metrics demonstrate low absolute error and an extended effective measurement range, illustrating robustness across diverse imaging scenarios. This work establishes a new paradigm in which polarisation information is co-registered with depth, paving the way for comprehensive 3D sensing of challenging materials and environments.

Optical Measurement Techniques for 3D Surface Profiling publication trend

The graph below shows the total number of articles in optical measurement techniques for 3d surface profiling across all publications each year (not limited to Nature Index journals).

Technical terms

Interferometry: Optical technique exploiting interference of coherent light waves to detect minute surface height variations with subwavelength sensitivity.

Structured light: Method that projects known spatial patterns onto a surface and analyses distortions in the captured image to calculate depth information.

Fringe projection profilometry: Structured-light variant using sinusoidal or coded fringes to retrieve phase maps that are unwrapped into 3D surface profiles.

Phase unwrapping: Computational process that converts wrapped phase measurements, which are modulo-2π, into continuous phase maps corresponding to true surface height.

Polarisation structured light: Technique combining depth-encoding patterns with polarisation control to separate specular reflections and enhance measurement robustness on reflective or transparent surfaces.

References

1. Physics-informed deep learning for fringe pattern analysis. Opto-Electronic Advances (2024).
2. Deep-learning-enabled temporally super-resolved multiplexed fringe projection profilometry: high-speed kHz 3D imaging with low-speed camera. PhotoniX (2024).
3. Modeling the measurement precision of Fringe Projection Profilometry. Light: Science & Applications (2023).
4. Polarization structured light 3D depth image sensor for scenes with reflective surfaces. Nature Communications (2023).
5. Generative deep-learning-embedded asynchronous structured light for three-dimensional imaging. Advanced Photonics (2024).