Temprofile - Example 1: Quadrilayer Magneto-optical Disk

Simulation Software for Laser Heating of Multilayer Stacks

Example 1: Quadrilayer Magneto-optical Disk

Simulated in this example is a quadrilayer stack consisting of a plastic substrate coated with a 32 nm-thick layer of aluminum, a 72 nm-thick layer of SiO₂, a 12 nm-thick layer of magnetic film, and another 100 nm-thick layer of SiO₂.

The Gaussian laser beam is incident on the stack from the surface side, its 1/e radius being 350 nm. The laser pulse shape is trapezoidal, having 60 nsec duration, with 10 nsec rise and fall times.

Calculated profiles of temperature versus x, y, z, and time are shown in Figures (a)-(d). Figure (e) shows the isotherms within the magnetic layer.

Shown below is the file TR01.SYS, which contains the structural parameters of the multilayer, the laser beam profile, and the mesh parameters. The filename extension .SYS stands for "system." This text file (originally created by TEMPROFILE) can be modified by the user, and may be subsequently imported to the program.

 !@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@#
 !                  @@ TEMPROFILE 5.0     File TR01.SYS @@                 #
 !                  @@ Date: 12/31/1998     Time: 18:34 @@                 #
 !                  @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@                 #
 !                                                                         #
 ! Notes: Quadrilayer stack used in the surface-incidence configuration    #
 !        of Test Run 1. The incident beam has a Gaussian profile.         #
 !                                                                         #
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!#
 $                                                                         #
     Top/Bottom incidence: T                                               #
 $                                                                         #
  Substrate's index (n,k):    1.4600000       .00000000                    #
  Thermal constants (C,K):    1.7000000      2.00000000E-03                #
 $                                                                         #
         Number of layers:  4                                              #
 $                                                                         #
 Layer 01:  Thickness,n,k:    32.000000       1.2000000       6.9000000    #
                      C,K:    2.7000000       2.4000000                    #
 $                                                                         #
 Layer 02:  Thickness,n,k:    72.000000       1.5000000       .00000000    #
                      C,K:    2.0000000      1.50000000E-02                #
 $                                                                         #
 Layer 03:  Thickness,n,k:    12.000000       3.1000000       3.5000000    #
                      C,K:    2.6000000       .16000000                    #
 $                                                                         #
 Layer 04:  Thickness,n,k:    100.00000       1.5000000       .00000000    #
                      C,K:    2.0000000      1.50000000E-02                #
 $                                                                         #
 Heat loss factor (GAMMA):    .00000000                                    #
 $                                                                         #
    Incident beam profile: Gaussian                                        #
                Lambda,R0:    632.80000       350.00000                    #
 Impulse: POWER,TAU,NSTEP:    1.0000000       1.0000000             5      #
 $                                                                         #
 Mesh:         RMAX,DLTAR:    2000.0000       25.000000                    #
               ZMAX,DLTAZ:    400.00000       4.0000000                    #
                     TMAX:    100.00000                                    #
 !@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@#

The file TR01.PLS shown below contains the laser pulse shape. (The extension .PLS stands for "pulse.") Pairs of points (t, P) at the corners of the piece-wise linear function P(t), initially entered from the keyboard, are saved in this file. The user can modify the contents of this file with a text editor, and import it to the program environment during subsequent runs of TEMPROFILE.

!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@#
!                  @@ TEMPROFILE 5.0     File TR01.PLS @@                 #
!                  @@ Date: 12/31/1998     Time: 18:34 @@                 #
!                  @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@                 #
!                                                                         #
! Notes: Trapezoidal pulse shape of the laser beam. The rise and fall     #
!        times are 10 nsec each, and the total pulse width is 60 nsec.    #
!                                                                         #
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!#
    Point on pulse (t,P):    10.000000       2.0000000                    #
    Point on pulse (t,P):    50.000000       2.0000000                    #
    Point on pulse (t,P):    60.000000       .00000000                    #
    Point on pulse (t,P):    100.00000       .00000000                    #
!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@#

(a,b) Plots of temperature versus x and y at z = 108 nm computed in Example 1. Since the incident beam is circularly symmetric and does not move relative to the multilayer stack, the temperature profiles along X and Y are identical.

(c) Temperature versus z at (x, y) = (0, 0) at several instants of time.

(d) Temperature as function of time at z = 108 nm

(e) Isotherms in the XY-plane at z = 108 nm and time = 50 ns, as computed in Example 1. The hottest spot at the center has temperature T = 194.13�C (above ambient). The plotted isotherms, starting in the middle and moving outward, correspond to T = 193�C, 180�C, 160�C, 140�C, 120�C and 100�C.

What is TEMPROFILE? What Can TEMPROFILE Do? Laser Beam Profile, Pulse Shape, and Velocity Functional Units of TEMPROFILE Platforms and Operating Environment Pricing and Service Policy	Examples: Quadrilayer Magneto-optical Disk Quadrilayer Stack Illuminated through Substrate User-defined Laser Beam Profile