clex23.in : Optical Simulation of Liquid Crystal in the In-plane Switching (IPS) Mode
Requires: Victory Process / Clever
Minimum Versions: Victory Process 7.14.3.R / Clever 3.11.6.C or Later
This example demonstrates the electrical and optical simulation of a liquid crystal (LC) cell in the in-plane switching (IPS) mode. On one hand, the LC director reorientation in the presence of external electric field is calculated by a finite element method. On the other hand, the optical transmission of a light beam traveling through the LC cell is calculated by the extended Jones matrix method.
This example is related to the 2017 Silvaco Simulation Standard article: "Optical Simulation of Liquid Crystals in the In-plane Switching Mode".
Everything about the optical part is specified in the optics statement. An existing structure file which is the output from an electrical simulation is necessary and can be imported via structure. The corresponding bias voltage is defined in pixelvolt. A tabular file with the dispersion relation of the complex refractive index of the LC is assigned to indexfile. The propagation direction of the light source is defined in lightorient. Appropriate optical grids need to be specified by dx, dy, and dzmax.
There are two types of polarizers in the optical simulation. One type is the ideal polarizer whose physical thickness is zero. The optic axis in the beam-incident plane is defined in polanglestart and that in the beam-outgoing plane is defined in polangleend. The corresponding real part of the polarizer?s refractive index is specified in polindexstart and polindexend. Another type of polarizers is the non-ideal polarizer which is a birefringent optical layer. The ideal polarizer must be first disabled by setting its polarization angle out of the range between -90 and 90 degrees. The properties of the non-ideal polarizer is specified in StartEndLayers(). The first six variables of this function are the layer thickness, optic axis, no, ne, ko, and ke for the polarizer at the incident plane, while the last six are related parameters for the one at the emitting plane.
The fixed beam wavelength is defined in wavelength and the fixed incident angle is defined in angle. The transmission pattern is saved to the file assigned to topview. The wavelength sweep simulation is trigged by specifying a wavelength range in wlsweep(). The output spectral file is specified in outspec. The angular sweep is done by specifying the scan range of the polar and the azimuthal angle in anglesweep() and thetasweep() , respectively. The angular distribution of the transmission is saved to the file assigned to angleview.
To load and run this example, select the Load button in DeckBuild > Examples. This will copy the input file and any supporting files to your current working directory. Select the Run button in DeckBuild to execute the example.
Input Deck
# This example demonstrates the electrical and optical
# simulation on an in-plane switching (IPS) cell.
# The pixel layout consists of two zigzag electrodes.
##
go VictoryProcess
init material=oxide GasHeight=5 Depth=1 from="0,0" to="10,30"
# Create one mask with two electrodes.
SpecifyMaskPoly maskname=ELEC p1="2.5,1" p2="0.5,15" p3="2.5,29" p4="4.5,29" p5="2.5,15" p6="4.5,1" electrode="Pix"
SpecifyMaskPoly maskname=ELEC p1="7.5,1" p2="5.5,15" p3="7.5,29" p4="9.5,29" p5="7.5,15" p6="9.5,1" electrode="Com" add
line x position=0 spac=0.25
line x position=10 spac=0.25
line y position=0 spac=0.25
line y position=1 spac=0.5
line y position=15 spac=0.5
line y position=29 spac=0.5
line y position=30 spac=0.25
line z position=-5 spacing=1
line z position=-3 spacing=0.1
line z position=-1.5 spacing=0.1
line z position=-0.05 spacing=0.025
line z position=0 spacing=0.1
line z position=1 spacing=1
# Pattern electrodes.
deposit material="ITO" thick=0.05 min
mask "ELEC"
etch material="ITO" thick=0.05 min
strip
electrode mask="ELEC" material="ITO"
deposit material="LC" thick=3 min
deposit oxide thick=1 min
save name=clex23_0
## Create a Conformal Mesh Structure File ##
go victorymesh
load in=clex23_0
remesh conformal
save out=clex23_1.str
# The electrical simulation is carried out in the following section.
go clever
init structure="clex23_1.str"
material ITO conductivity=1000
material oxide permittivity=3.9
# Specify the anisotropic permittivity and the elastic constants of the LC.
setLC epsParaDir=10.7 epsVertDir=3.7 splay=14.4e-12 twist=6.9e-12 bend=18.3e-12 cPenalty=1000
# Specify the rubbing angle and the pre-tilt angle on the top and at the bottom of the LC region.
LCbndaryB partition(0,10) rubAngle(90) tiltangle(1)
LCbndaryT partition(0,10) rubAngle(90) tiltangle(1)
solver linearsolver=pam pamsolver=gmres ddprecond=RAS preconditioner=amp multilevel=0 fillratio=1.e-3 lsmaxiter=200 lstolerance=1.0e-10 nlsmaxiter=100 nlstolerance=1.0e-8
option LSconvergeinfo=1 NLSconvergeinfo
# Ramp the pixel voltage to 6V with a step of 0.5V.
# Save the structure at each 0.5V interval from 0 to 6V.
setPixelBias("Pix",0,0.5,1,1.5,2,2.5,3,3.5,4,4.5,5,5.5,6)
Interconnect Capacitance domainboundarycondition=cyclic savestep=0.5 structure="clex23"
# Save the parasitic capacitance netlist.
save spice="clex23.net"
tonyplot3d clex23.V6.str -set clex23_0.set
# The optical simulation is carried out in the following section.
# The beam is set to propagate from the maximum z toward the minimum z.
# Crossed ideal polarizers
go clever
# Loops are used to calculate the optical transmission at different bias voltages.
# The wavelength and the incident angle of the monochramatic source beam
# is defined as 0.55 microns and 0 (normal incidence), respectively.
# The transmittance and the reflectance can be read from the runtime output.
set Volt=0
loop steps=13
optics structure="clex23.V$'Volt'.str" indexfile="clex23_LC_index.txt" pixelvolt=$Volt \
wavelength=0.55 angle=0 lightorient=fromtop polanglestart=0 polangleend=90 \
dx=0.25 dy=0.5 dzmax=0.1 polindexstart=1.5 polindexend=1.5 \
topview="ips_V$'Volt'_top"
# TMMmethod=TMM4x4
set Volt=$Volt+0.5
l.end
tonyplot ips_V1_top.str ips_V2_top.str ips_V3_top.str ips_V4_top.str ips_V5_top.str ips_V6_top.str -set clex23_topview.set
# The wavelength scan starts from 0.39 microns and ends at 0.75 microns
# with a wavelength step of 10nm.
set Volt=4
loop steps=5
optics structure="clex23.V$'Volt'.str" indexfile="clex23_LC_index.txt" pixelvolt=$Volt \
wlsweep(0.39,0.75,0.01) angle=0 lightorient=fromtop polanglestart=0 polangleend=90 \
dx=0.25 dy=0.5 dzmax=0.1 polindexstart=1.5 polindexend=1.5 \
outspec="ips_V$'Volt'_spec"
# TMMmethod=TMM4x4
set Volt=$Volt+0.5
l.end
tonyplot -overlay ips_V4_spec.log ips_V4.5_spec.log ips_V5_spec.log ips_V5.5_spec.log ips_V6_spec.log -set clex23_spect.set
# The full range of the polar and azimuthal angle is scanned in a 5-degree step.
set Volt=0
loop steps=2
optics structure="clex23.V$'Volt'.str" indexfile="clex23_LC_index.txt" pixelvolt=$Volt \
wavelength=0.55 lightorient=fromtop polanglestart=0 polangleend=90 \
dx=0.25 dy=0.5 dzmax=0.1 polindexstart=1.5 polindexend=1.5 \
anglesweep(0,90,5) thetasweep(0,360,5) angleview="ips_V$'Volt'_angle"
# TMMmethod=TMM4x4
set Volt=$Volt+5
l.end
tonyplot ips_V0_angle.str -set clex23_angle.set
tonyplot ips_V5_angle.str -set clex23_angle.set
# Crossed non-ideal polarizer
go clever
# The ideal polarizers are disabled by setting their polarization angles to be 100.
set Volt=0
loop steps=13
optics structure="clex23.V$'Volt'.str" indexfile="clex23_LC_index.txt" pixelvolt=$Volt \
wavelength=0.55 angle=0 lightorient=fromtop polanglestart=100 polangleend=100 \
dx=0.25 dy=0.5 dzmax=0.1 \
StartEndLayers(180, 0, 1.5, 1.5, 2e-05, 0.002; 180, 90, 1.5, 1.5, 2e-05, 0.002) \
topview="ips_V$'Volt'_top_pol"
# TMMmethod=TMM4x4
set Volt=$Volt+0.5
l.end
tonyplot ips_V1_top_pol.str ips_V2_top_pol.str ips_V3_top_pol.str ips_V4_top_pol.str ips_V5_top_pol.str ips_V6_top_pol.str -set clex23_topview.set
quit