This section describes how to use the import object to create structures from an image. Images can be imported from JPG (*.jpg) or PNG (*.png). Other image types can be exported to these two formats in most image editing software.
Selecting the Import Image button in the main toolbar will open the Image Import Wizard. The wizard provides a simple interface to import, threshold, crop and scale the image. The image is used to define the objects shape in the XY plane. The object is extruded in the Z direction.
Image Import wizard
STEP 1: Add import object with the image import wizard.
A) Click on the Import button expansion arrow in the main toolbar and select the Image option to open the Image import wizard.
B) Click "Select Image" to choose your image file
STEP 2: Set threshold
The import process takes a color or grayscale image and converts it into a binary representation of the structure. The threshold which defines what portion of the image will be set to be the background index of the simulation region is defined with the THRESHOLD slider.
The “invert” button can be used to invert the image
STEP 3: Set scale
Once the image has been imported, it is necessary to calibrate the length of the structure.
Here, with GRAPH CONTROL selected, the user can drag a rectangle and use the horizontal, vertical, or diagonal dimension of the rectangle to define the size of the imported structure.
For this example, we use the fact that the period is 270nm, or that 10 periods is 2.7 microns.
STEP 4: Crop image
With the “crop image” and “crop” items selected, the image can be cropped using the mouse to define a rectangular region.
Once a rectangle has been dragged within the plot area region, its edges can be dragged to the correct location.
STEP 5: Review result
The last step of the import wizard allows you to accept the structure as depicted, or move back through the steps to make modifications.
See imported object in the CAD layout editor.
When the image import wizard is finished, you will see the imported object in the CAD layout editor.
Note: Drawing resolution
Initially the object will be drawn at a low resolution, as shown in the top half of this figure. You can increase the drawing resolution with the settings on the Graphical rendering tab. The bottom half of this figure shows the object displayed at the same resolution as the image that is was imported from. It is important to note that the graphical rendering does not affect the simulation. Irrespective of the drawing resolution, the meshed object used for the simulation is always as has been defined.
Fine scale adjustment
In order to open up the wizard to adjust the fine scale, click on the "Adjust image scale" button in the "Import data" tab of the import object's edit window as shown below.
STEP 1: Verify settings
Drag the ruler to a desired horizontal, vertical or diagonal length. Check that the distance from A-B is what you expect.
Verify lengths in at least 2 different directions.
STEP 2: Define one length
Choose a direction to recalibrate your scale, for example, horizontal. Drag the ruler over a known length, enter the “distance A-B should be” setting and hit Apply. The distance A-B will now be precisely what you defined.
STEP 3: Define a second length
Verify that your structure has the correct length in a direction different to the one used in STEP 2. If the length is not correct, choose to “define two lengths”. Select “calibrate length 2” and drag the ruler to define a second length, for example, diagonal. Enter the desired distance A-B for the second length and hit Apply. You can now verify that both lengths are correct.
Hit Done when you are satisfied with your calibration. The x scale and y scale settings will be automatically updated to reflect your desired changes.