Ablation of materials with double time-separated laser pulses
- Kryptis: Lazeriai
Laser ablation and processing of materials is applied in various applications ranging from consumer electronics to specific medical applications. Ultrashort laser pulses used for high-quality processing of transparent materials, are not enough efficient as the laser energy is absorbed via multiphoton absorption, and much of energy is lost. Meanwhile, long pulses (of nanosecond range) rely on heating intrinsic free electrons which may be distributed unevenly in the material, and in combination with the long duration, the heat-affected areas are evident in the processed material. The present invention discloses a method and system of laser ablation with improved efficiency, employing focused femtosecond/picosecond dual-pulse irradiation. The femtosecond pulse first excites local free electrons of the material into the conduction band, and then the excited electrons are heated and multiplied via impact absorption of the subsequent picosecond pulse, resulting in efficient ablation of the material.
Inventors: Vytautas Jukna; Simas Butkus; Dangirdas Šulnius
Jurisdiction: EP.