Direct Laser Writing

• Spot sizes ~1 - 5um
• Tightly Focuses, modulated He-Cd or Argon-ion laser scanned across photresists surface
• Up to 256 phase levels
• Serial Process
• Difficult to accurately transfer structure into substrate
• Direct ablation of polyimide layer on substrate using an excimer laser is also possible
• Pattern can be transferred to a VHOE by processing in a 4f optical processor.