RSoft Enewsletter

November 2015

Using WinPLOT to Create High-Quality Graphics for Publications and Presentations: Part 2, Contour Plots

High-quality graphics are required to accurately present simulation results in publications and presentations. WinPLOT, the plotting program included with all RSoft™ products, has a complete set of options that can be used to customize how you display data. We have illustrated how to use WinPLOT to create high-quality line plot in the previous enews.  In this note, we will illustrate how to make high quality contour plots.  We will use the same nano-scale structured color example to show the options that can be used to customize contour plots; future notes will discuss other types of plots and options.  You can access the design files on the Customer Portal

A contour map of the field in the structure can be produced with the spatial field output feature of DiffractMOD™ (RCWA). The plot shown in Fig 1a was produced using an aspect ratio of 1 and a structure outline.  However, quite frequently, users need to customize the plot in different ways.  We have previously learned that we can go to the View Editor tab in WinPLOT and modify the commands according to our needs.  If we replace the old ones with the commands in Table1, we will get the plot shown in Fig.1b.

magnetic field

Fig. 1: (a) Amplitude distribution of magnetic field 
(b) Intensity distribution of magnetic field

Table 1: Modified WinPLOT Commands

!*Objects: Indicates that the draw objects command starts.
/t"\C15Ag":-0.075,0.18 Sets text object position and color. The \C command sets a color for the inserted text.
/t"\C15SiO2":-0.075,-0.034 Sets the text object position and color.
/ats1.3 Sets the text size.
!*End. Indicates that the draw objects command ends.
/frm0 Sets the axis frame lines off.
/tkm0 Sets the tick mark display off.
/lbl0 Sets the tick mark labels display off.
/powy2 Command to square contour value.  This is used to display the intensity of the magnetic field.
/cont Contour map command.
/drawa'fig1_custom.pda' Display the custom structure online file fig1_custom.pda. See note below table for more details *.
/cscl"pbgpos.scl" Chooses color scale.
!/cscld0 Sets color bar off.  “!” cancels this option.
/zw0 Scales color scale to match the data and sets the minimum 0.
/aspect1 Sets aspect ratio=1.
fig1_hy.dat           Plot data file.


*We created the custom structure outline shown in Fig1b. The contents of this text file (fig1_custom.pda) are:

fill 0
color 15
style 1
width 3
line -0.09 0 -0.025 0
line -0.025 0 -0.025 0.17
line -0.025 0.17 0.025 0.17
line 0.025 0.17 0.025 0
line 0.025 0 0.09 0

Please refer to section 9.B. of the WinPLOT manual for more details about using RSoft drawing files. 

We can also simulate the angle-resolved reflection spectral contour plots at different periods.  Fig. 2 is obtained by a MOST™ scan vs. wavelength and internal incident angle scan in DiffractMOD. To display the results, the plot commands are modified using the ones in Table 2.

Angle resolved reflection spectra at P=140nm

Fig. 2:  Angle resolved reflection spectra at P=140nm

Table 2: Modified WinPLOT Commands for Angle-Resolved Reflection Spectra

/cont3,2/lw1.2/lc9 Displays the contour map as both color coded and with line plots.  /lw /lc sets up the line width and color.
/xl"Angle(&2)" Axis label. “&2” displays the special character for degrees.
/yl"Wavelength(nm)" Axis label.
!/tt"Meas. dm\_de\_r\_total\_vs\_phi:  y" Comment out the title command with the ‘!’ character.
/cscl"spectrum.scl" Sets the color scale.
/sq1000 Scales the value of the contour plot by 1000x. /sy will scale the value of the y-axis.
/zw0 Scale color scale to match the data and sets the minimum to 0.
/clev:0.1,0.4,0.8,1 Sets the display contour line levels.
Fig3a_dm_de_r_total_vs_phi.dat Data file.


We also can use WinPLOT to display multiple plots together.  The following is a set of 4 plots corresponding to 4 periods of the above angle-resolved reflection spectra.

Angle resolved reflection spectra at P=140nm, 180nm, 220nm, 260nm

Fig. 3: Angle resolved reflection spectra at P=140nm, 180nm, 220nm, 260nm

The following WinPLOT commands are used to plot the above figure:

Table 3: WinPLOT Commands for Displaying Multiple Plots Together

/fscl0.8 Sets font scale.
/page2,2 Indicates there are four plots in this graph.
/plot1,2 @Fig3a_dm_de_r_total_vs_phi.pcs Sets the plot at most top left corner in the page.
/plot2,2 @Fig3b_dm_de_r_total_vs_phi.pcs Sets the plot at most top right corner in the page.
/plot1,1 @Fig3c_dm_de_r_total_vs_phi.pcs Sets the plot at most lower left corner in the page.
/plot2,1 @Fig3d_dm_de_r_total_vs_phi.pcs Sets the plot at most lower right corner in the page.


Please note that when displaying multiple plots together, you should put all these plots (.pcs files) in the same location. 

There are many more WinPLOT commands that can be used to modify contour plots. Please consult the WinPLOT user guide or contact the RSoft Technical Support team at rsoft_support@synopsys.com for more information.


References

[1,2]  Yi-Kuei Ryan Wu et al, “Angle-Insensitive Structural Colours based on Metallic Nanocavities and Coloured Pixels beyond the Diffraction Limit,” Scientific Reports, 3 (2013).

Webinar Recordings Now Available on the Customer Portal

These webinars are now available in the RSoft section on the Customer Portal.

Mixed-Level Simulation: Using RSoft Products to Model Sub-Wavelength Features in LightTools

In this 25-minute recording, learn about a mixed-level methodology that unifies the use of EM wave-level (RSoft) and ray-level (LightTools®) tools. The approach uses the RSoft products to characterize micro/nano-structured surfaces and include coherent effects in a LightTools simulation, such as scattering due to sub-wavelength structures, diffraction, and polarization.

Modeling Polarization-Multiplexed Coherent Fiber-Optic Communication Systems in OptSim™

View this 30-minute recording to learn about how high-speed, polarization-diversity systems yield spectrally efficient data transmission over longer distances. During the webinar, modeling options available in OptSim for PM-QPSK and PM-mQAM transmitters, receivers and digital signal processing used in coherent transmission were demonstrated.