STP954

    Angular Dependence of Multilayer-Reflector Damage Thresholds

    Published: Jan 1986


      Format Pages Price  
    PDF (168K) 10 $25   ADD TO CART
    Complete Source PDF (8.6M) 10 $66   ADD TO CART


    Abstract

    The damage resistance of HfO2/SiO2 multilayer dielectric reflectors was measured as a function of angle of incidence with 351-nm XeF-laser irradiation. The laser produced nominal 10-ns pulses at a repetition rate of 35 pps. A series of reflectors designed for 0°, 30°, 45°, 60°, 75°, and 85° was tested with an S-plane polarized beam. To account for variations in the separate coating depositions, some of the coating designs were tested at two angles of incidence. At large angles of incidence, we did not observe the anticipated large increases in damage threshold predicted theoretically on the basis of spatial dilution (1/cosθ) of the intensity at the reflector surface and standing-wave electric fields. For example, the threshold for a reflector designed and tested at 85° was only a factor of 2.5 larger than that of normal-incidence reflectors tested at 0°. Several possible mechanisms to explain this discrepancy were considered.

    Keywords:

    coating defects, free-electron lasers, grazing-incidence reflection, hafnium oxide, laser damage thresholds, multilayer reflectors, multiple-shot laser damage, silicon dioxide, standing-wave electric fields, thin films, ultraviolet reflectors, xenon fluoride lasers


    Author Information:

    Newnam, BE
    Los Alamos National Laboratory, Los Alamos, New Mexico

    Foltyn, SR
    Los Alamos National Laboratory, Los Alamos, New Mexico

    Gill, DH
    Los Alamos National Laboratory, Los Alamos, New Mexico

    Jolin, LJ
    Los Alamos National Laboratory, Los Alamos, New Mexico


    Paper ID: STP23135S

    Committee/Subcommittee: F01.02

    DOI: 10.1520/STP23135S


    CrossRef ASTM International is a member of CrossRef.