The Exhaustive Search method is a global optimization algorithm that systematically evaluates all possible combinations of layer thicknesses within predefined bounds. Unlike heuristic or pruning-based methods, Exhaustive Search leaves nothing unexplored, making it the most straightforward yet computationally intensive way to identify an optimal thin-film design.
In this approach, each layer’s thickness is discretized into a fixed number of candidate values between a lower and upper bound. All combinations of these values across the stack are then evaluated, and the best design is chosen based on the merit function.
Advantages
- Complete exploration: Evaluates every possible configuration within the specified discretization.
- Global optimality (within discretization): Guarantees the best solution among the tested candidates.
- Conceptually simple: Easy to understand.
Limitations
- Extremely high computational cost: Runtime grows exponentially with the number of layers and discretization levels (combinatorial explosion).
- Discretization trade-off: Coarse discretization is fast but less accurate; fine discretization is precise but often impractical.
- Impractical for large stacks: Useful primarily for very small problems or validation.
- Highly Parallelizable: Candiate stacks can be evaluated independently.
In FilmOptima
In FilmOptima, Exhaustive Search belongs to the Global Optimization category of algorithms.
| Parameter | Description |
|---|---|
| ↓ Thickness | The lower bound for candidate layer thicknesses. |
| ↑ Thickness | The upper bound for candidate layer thicknesses. |
| # Thicknesses | Number of equally spaced candidate thickness values between the lower and upper bounds. Higher values increase precision but also runtime. |