ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Photothermal laser ablation is studied using poly-(methyl methacrylate) films doped with a dye, IR-165, which functions as a molecular heater and thermometer. Direct optical measurements of temperature are performed on samples heated by 100 ns near-IR pulses at 1.064 μm, at rates dT/dt≈5×109 deg/s. Below ablation threshold, the heat capacity measured by optical calorimetry is precisely the value obtained by conventional calorimetry. At ablation threshold, the peak surface temperature is Tabl=600 °C. The increase in heat capacity observed above threshold, together with the results of a conventional thermal analysis, is used to determine the weight fraction of material decomposed at ablation time χth=0.02. With increasing pulse energy, the fraction decomposed increases and a more forceful ablation is observed, but the surface temperature does not continue to increase past Tlim=715 °C, which is determined to be the limiting temperature for thermal decomposition.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.351589
Permalink