Floating Constants

A new big addition to OptiLayer design capabilities: supporting floating constants for all targets.

It is possible to specify only constant offset, or more complicated offsets depending on frequency: \(C_1+C_2\cdot\omega\) or \(C_1+C_2\cdot\omega+C_3\cdot\omega^2\).

These new options are important for designing of ultrafast coatings in the case when a constant/linear/parabolic GD/GDD are required.

The option is useful also in general case, when, for example, it is necessary to design a coating with constant T/R in some spectral region, and the absolute value of this characteristic is not important.

Example (right panel): target transmittance is to be flat in the spectral range in the visible spectral range; transmittance must be in the corridor from 60% to 90% and from 15% to 35% in the spectral ranges from 400 to 570 nm and from 630 to 800 nm, respectively.

constant spectral transmittance
Linear T

There are three types of floating constants:

  • \(C_1\) - spectral characteristics are as flat as possible;
  • \(C_1+C_2\cdot\omega\) - spectral characteristics are linear with respect to the frequency \(\omega\) (example in the left panel); 
  • \(C_1+C_2\cdot\omega+C_3\cdot\omega^2\)   - spectral characteristics are parabolic with respect to \(\omega\)
Target specification: you should specify two pages for each desired spectral range. In the first page you should indicate a floating constant type: In the second page you specify the allowed limits of the spectral characteristics using range targets:
FloatingConst TargetSpec 1 FloatingConst TargetSpec 2