OCT Optical Coherence Tomography

OCT (Optical Coherence Tomography) is emerging as a very promising high resolution 3D imaging technology with a large range of applications in industrial non-destructive surface inspection and non-invasive medical examinations.

Working with light sources in the near infrared, OCT has less penetration than standard ultrasound techniques, but improves on ultrasound resolution by more than a factor of 10.

The technology is based on the interference of light rays reflected in a reference and sample arm. Constructive interference is observed as an intensity maximum in an OCT detector when the optical paths of both arms are exactly equal. Therefore by tuning the length of the reference arm to bring forth the appearance of the interference signal, a precise determiantion of the position of the reflection point in the sample is possible.