Technical Issues - Designs on Multiple Substrates I

In the following discussion we assume that substrate surfaces are parallel and that multiple reflections between surfaces are added incoherently. Click here for a further discussion. In some cases surfaces are purposely wedged (not parallel); see Designs on Multiple Substrates II.

DESIGN 2.61.0317 added Edit...Reverse Segment to the Groups Mode design editor. This helps users combine designs onto one or more substrates. While designs can also be reversed in the Design Macro editor, it may be more simpler to do so in the Groups Mode editor.

This section reviews a technique for combining multiple designs. Both entrance medium (AIR) and exit medium (SUB) have index 1.0. Previously designed Lowpass and Highpass filters are opened in the Groups Mode macro editor as shown here. When treated as a normal one-side design, the H layer will be next to the glass substrate.

Effectively the design is deposited onto AIR and the substrate is treated as a massive layer.

The sequence for combining designs is shown below.

1. Starting design is 2G (2 mm glass). Verify that Film Indices includes all materials to be utilized as designs are added. When using optical thickness, the final design will have the same design wavelength as the original design.
2. Insert Lowpass design before 2G with Macro...Insert 1 (<Shift+F1>). Do  not change the displayed Wavelength entry unless you need to shift the inserted design.
3. Insert Highpass design after 2G with Macro...Insert 2 (<Shift+F2>).
4. Lowpass is backwards! Highlight the lowpass stack and click Edit...Reverse Segment (<Ctrl+S>). Alternatively, the design can be reversed in the macro editor.
5. The final design now has the Lowpass outer H layer adjacent to glass.


Download WideBandpass.faw and copy to  ..\Winfilm\Designs to try the above example.

The Lowpass Only curve was plotted after ignoring the highpass stack (layers 26-47) in the Layers Mode design editor.