Exhaustive Search

Exhaustive search is the new design option of OptiLayer. In order to apply this option you need to specify a starting design. Typically, this option can be applied in cases when you need a design of special structure or you are looking for a design of a specific structure. 

Exhaustive search option is not random, but deterministic procedure, very straightforward and known for a very long time. Nevertheless it is convenient to launch this search using the same Random Optimization Parameters dialog, since settings are quite similar:

Synthesis –> Random Optimization –> Search tab

Exhaustive Search procedure performs the analysis of the Merit Function considering all designs in the specified hypercube in accordance with the dialog settings. At modern computers up to several dozens of millions combinations (shown on the top) are acceptable.

Exhaustive Search procedure could be significantly accelerated with reasonable specifications of the expected Physical or Optical thickness, or QWOT, or FWOT.

Each of the selected active layer thickness is changed from minimum Th.Min to maximum Th.Max value with the specified step N of Steps. The Merit Function of each design is calculated and the best designs are placed to the Collection.

Example: Designing a color coating using metal-dielectric films.

Colors of the light reflected from the front and back sides are dark yellow and violet orange.

Layer materials are \(TiO_2\), \(SiO_2\) and \(Ag-SiO_2\) metal-dielectric composite.

Specifics of the design problem:

• Metal layer is surrounded by \(SiO_2\) layers;

• Thickness of the metal-dielectric layer is fixed and equal to 12 nm because optical constants of such films are reliably known;

• Due to technological reasons thicknesses of the surrounding \(SiO_2\) layers are not less than 78 nm;

• Minimal possible number of layers are required.

Starting design: 6-layer design, the first layer is \(TiO_2\) (see above)

Color patch of the found 6-layer design shows how the colors of the reflected and back side reflected light vary with respect to the incidence angle range from 0 to 60 degrees:

Best designs are stored in Collection.