TFCalc 3.2 Changes

Major New Features

These features and many others are described in more detail below. The page numbers refer to pages in version 3.2 of the “Guide to TFCalc”.

Automatic Optimization Targets. This is a very significant addition to TFCalc’s features. Previously, every time you optimized a design, you had to decide on the number and location of the optimization targets. Now TFCalc can do this for you! This feature will make designing thin film coatings easier than ever. There are now two kind of targets: discrete (the targets used in the past) and continuous; TFCalc has a data window for each. A continuous target consists of a beginning and ending wavelength and a beginning and ending target. For example, a continuous target could be R = 0 from 400 to 700 nm.
During optimization, TFCalc determines automatically how the continuous target is evaluated (i.e., the number and location of the target wavelengths). Continuous targets work with all of TFCalc’s features that use targets: local optimization, needle optimization, tunneling, and layer sensitivity. It is possible to use both discrete and continuous targets to design a coating. (See pages 19, 31, 33, and 44.) For an example of a coating designed with continuous targets, click here.
Improvements in the Tunneling Method. In TFCalc 3.1, the tunneling method would sometimes fail to determine which layer to grow. Now it succeeds almost always, and displays an error message if tunneling cannot continue.
Improvements in the local optimization methods.

Quartiles in Sensitivity Analysis. Previously, the sensitivity analysis produced two curves: the worst-case minimum and maximum performance. Now TFCalc also computes three additional curves: the quartiles. The second quartile is the median performance. (See pages 35, 40, 46, and 48.)
The smallest percentage change in now 0.01% sensitivity parameters dialog.

Constraints in the N and K Computation. When you fit measurements to a dispersion formula,, it is possible to indicate which parameters in the dispersion formula should be optimized and to constrain the values of those parameters. (See page 56.)
During the optimization of the N and K parameters, the “Stop” button now responds faster.
Increased the maximum number of data points in each dataset to 1001.
In tables of refractive index, increased the maximum number of data points to 1001.

When the front or back layers are printed, the reference wavelength is now printed also.
All incident angles are forced to be less than 89.999 degrees.
TFCalc now reads comma-delimited files, which are produced by some spectrophotometers.
In the monitoring chart, the thickness of the monitoring chip was always 1 mm. For　dielectric chips, this was not a problem.