Essential Macleod v8.15.174

The Essential Macleod program contains all the essentials for the design and performance calculation of optical coatings. In particular it will calculate a wide range of performance parameters of a given coating design including the usual reflectance and transmittance magnitude and phase, but also color, ultrafast, ellipsometric quantities and from the zero’th up to the third derivative as a function of wavelength. It will estimate the effects of random errors in the layers. It will refine existing designs to improve their performance and it will synthesize designs that start with virtually no instructions other than the materials to be used and the performance that is targeted. It includes allowance for layer packing density. It has powerful design editors to make it very easy to create or change even the most complex designs. It also maintains the files that contain the optical constants of materials. The Essential Macleod will also calculate performance of series of different substrates, with or without associated coatings and it will perform a wide range of analytical functions such as generating admittance diagrams and electric field distributions. It has a completely flexible system of variable units.

The Essential Macleod is equipped to export coating designs to the ZEMAX and Code V optical design packages, It will also export performance to the LinkSIM simulation tool.

Optional enhancements add a virtually limitless range of possible performance functions, run sheets and monitoring curves with links to thin film monitors.

The package is an integrated whole with the operation controlled almost entirely from menus. The menu commands are designed to permit the user to indicate what has to be done without needing to indicate how. To calculate an aspect of performance, for example, the user simply tells the package to produce a plot or a table. The underlying operation and organization is completely automatic. The description that follows, therefore, concentrates on the menu commands, what they are and what they do. It is purely a description of the operation of the software package. It does not go into details of the calculation techniques nor does it discuss design technique

The Essential Macleod uses a Multiple Document Interface (MDI). A document can be a plot, a table, a design, a list of materials and so on. Multiple Document Interface means that many documents may be displayed at once, the total number being limited by the capabilities of the computer and of the Windows installation. One document at a time is active. The menu bar changes as the active document changes so that the menu commands always apply to whichever of the open documents is the active one. For example, if a plot is active then the Edit menu will apply to the plot and will permit such things as changing the parameters of the axes. The user will find that it is often useful to be able to keep several designs open simultaneously. Should the capacity of Windows or of the computer be exceeded then the user will simply be requested to reduce the number of open documents. There is no need constantly to keep track of what is open. We do recommend, however, that unnecessary documents should be closed to avoid clutter.

Throughout the operation of the package, designs and specifications are saved to various files. The principal files are known as design files and they contain not just the sequence of layers but also the calculation parameters that should be used to evaluate the design. If a design is passed to refinement, the refinement specification also becomes part of the design file. The operation of saving the design and parameters can be manually performed at any time by choosing the appropriate menu item but it is also automatically initiated at those stages where there is a danger that something might otherwise be lost. In spite of this automatic feature, we do recommend that the user acquire the habit of saving the work at intervals. In particular when moving from one design to another it often seems convenient just to write the new design over the old. However, if the existing design is important the editing process will change it perhaps beyond recovery. No automatic save is initiated whenever a design is edited - editing is a very simple and straightforward process. Before beginning major editing, where a design is going to be substantially altered, it is good practice to save the design twice, once in the existing design file, thereby preserving the current design for later recall, and once in a new design file, which can then be edited without fear of changing the original. You may find this approach useful in other applications such as word processors also.

In the Essential Macleod the optical constant information for the thin film materials is kept in separate files in one or more materials databases. In the designs, the materials of the films and substrate are referred to explicitly by name (normally the chemical formula). A material database consists of a set of materials files together with control files that are kept in a separate folder, the path being the identifier for the database. Many different material databases may exist together. This is a particularly useful feature of the Essential Macleod and we encourage the user to make full use of it. Separate databases could be used, for example, for infrared materials as distinct from visible materials with wavelength stated in microns rather than nanometres. Alternatively, different databases could be used for different customers or for different plants or processes. In order to keep track of the particular database that was used to generate a design, information on both the database and the number/name conversion for the materials used, is stored in each design file. This information is compared with the existing database when a design file is read and only if an exact match is found can the calculations proceed without intervention. The material database can easily be changed but only when there are no open documents. The General command in the Options menu opens the form that contains the necessary command for changing the material database. A number of facilities are provided to simplify the maintenance of many different material databases. These are described later in the manual.