Process Steps for Coatings

Contamination of thin films occurs during deposition

  • Insufficient  cleaned vacuum chamber
  • Vacuum oil contamination
  • water vapor –> upon exposure to the atmosphere
  • During use –> plasma brone impurity deposition inside a gas laser
  •  During Cleaning –> inefficient cleaning/ during procedure and during storage
  • Inspection or transit –> lint from tissues, plastics from protective overlays and finger grease

All the above effects have been observed to increase the localized surface absorption, decrease Laser Induced Damage Threshold and  effect in optical coating process.

Reference: Laser damage in optical materials by R.wood