Investigation of optical damage mechanisms in hafnia and silica thin films using pairs of subnanosecond laser pulses with variable time delay

Journal Article · Sat Feb 01 04:00:00 EST 1992 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.351288· OSTI ID:5129912

Chase, L L; Hamza, A V; Lee, H W.H. ^[1]

---

1. University of California, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

Optical damage thresholds of submicron-thick, electron beam deposited HfO{sub 2} and SiO{sub 2} films on BK-7 substrates have been measured by monitoring the emission of neutral constituents during excitation with time-delayed pairs of 70-ps laser pulses at a wavelength of 1064 nm. The dependence of the optical damage threshold on time delay provides evidence of the optical damage mechanism. For SiO{sub 2}, linear absorption is the mechanism for energy deposition into the films by the laser beams. The data for HfO{sub 2} are less definitive, although linear absorption is the most likely damage mechanism. The behavior of the single-layer films is compared to multilayer HfO{sub 2}-SiO{sub 2} high-reflector coatings, for which a conditioning'' effect causes an increased optical damage threshold due to multiple pulse laser excitation at fluences below the single-pulse optical damage threshold.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5129912
• Journal Information: Journal of Applied Physics; (United States), Journal Name: Journal of Applied Physics; (United States) Vol. 71:3; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360605* -- Materials-- Radiation Effects
CHALCOGENIDES
DAMAGE
DOSES
ELECTROMAGNETIC RADIATION
FILMS
HAFNIUM COMPOUNDS
HAFNIUM OXIDES
LASER RADIATION
OXIDES
OXYGEN COMPOUNDS
PHYSICAL RADIATION EFFECTS
PULSES
RADIATION DOSES
RADIATION EFFECTS
RADIATIONS
REFRACTORY METAL COMPOUNDS
SILICON COMPOUNDS
SILICON OXIDES
THIN FILMS
THRESHOLD DOSE
TIME DELAY
TRANSITION ELEMENT COMPOUNDS