# Infrared Microscopy of Defects

| The strain field of dislocations shifts the polarization plane of light. A specimen (with two polished surfaces) between almost crossed polarizers thus transmits more or less light than the bulk around defects
| The picture shows two edge dislocations in GaAs parallel to the optical axis. The contrast is directly proportional to the sign and magnitude of the strain field (or stress-field, which is shown for comparison)

With frame

6.1.2 Infrared Microscopy

Stress Field of an Edge Dislocation

© H. Föll (Defects - Script)