Thermal and mechanical damage of GaAs in picosecond regime

✍ Scribed by Amit Pratap Singh; Avinashi Kapoor; K.N. Tripathi; G. Rvindra Kumar

• Book ID: 104159608
• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 834 KB
• Volume: 33
• Category: Article
• ISSN: 0030-3992
• DOI: 10.1016/s0030-3992(01)00038-x

✦ Synopsis

An in-depth study of the single pulse and multiple pulse laser (35 ps; 10 Hz and 1064 nm) damage for threshold uence and greater uence of GaAs 1 0 0 single crystal is presented. Damage which starts at a power 2×10 11 W=cm 2 in the form of pits occurs due to accumulation of laser induced microscopic defects. E ect of multiple pulse at ÿrst makes the pits more prominent in the form of Ga emission. Then the topmost layer is removed. If the number of pulses is further increased new pits are formed in the new surface (beneath the removed surface) and the above process is repeated. The thermal model is su cient to explain this morphology. However, for larger uences, a large cracking and fracture and the possibility of both Ga and As emission in di erent ratios suggest that mechanical damage is a dominant feature for higher uences which arises due to generation of shock waves and rapid vaporization of material. Damage threshold has been calculated with the help of the thermal model given by Meyer et al. which is in good agreement with our experimental results.