Refractive index profile

Fig. 1. Refractive index profiles of a 26-layer design: \(n(z)\) form.

Refractive index values are shown at the reference wavelength.

Important: In OptiLayer, layers are numbered starting from the substrate side.

Typically, \(n(z)\) is a step function taking high- and low-index values, \(n_H\) and \(n_L\).

At the same time, \(n(z)\) can be an arbitrary function as, for example, in the case of rugate filters.

Refractive index profile is re-plotted in the course of design process.

Fig. 2. Physical thicknesses of a 26-layer design.

Fig. 3. Switching refractive index profile into QWOT representation.Specification of the reference wavelength.

Optical thickness \(nd\) of a non-absorbing layer is calculated as:

\[nd=n(\lambda_0)\cdot d,\]

where \(\lambda_0\) is the reference wavelength specified in General Configuration menu (Fig. 3).

QWOT means that optical thickness of a layer is equal to \(\lambda/4\):

\[nd=\lambda_0/4.\]

In Thickness Units tab, you can switch between different representations of layer thicknesses.

Using Chart Editor, you can change the colors, line widths, axis etc.

Also, you can easily export profiles in numerical or graphical form into files of various formats (xls, png, jpeg, etc).

Fig. 4. For your convenience, you can change colors, line width etc. on all diagrams.