Working with the application
Application pages
The application workspace is parted into pages, which are accessed via the "Designer", "Beam", "Divergence" and "Modes loss" spines.
The laser cavity configuration is set on the first page in the fields "L" (laser cavity length), "RHR" (radius of curvature of the high reflecting mirror), "ROUT" (radius of curvature of the output mirror), "f" (focal length of the lens), "ZL" (coordinate of lens). On the same page, you need to set the wavelength in the "λ" field and the lens diameter in the "DL" field, which will serve as a vertical scale and be used in calculating the modes loss and beam divergence.
To set infinite values, type "inf". To enter a number containing a decimal exponent, the character "E" is used. For example:
5.3х105 → 5.3Е+5
0.7х10-7
→ 0.7Е-7
The values entered in the fields are accepted after confirming the input with the "Enter" key or when leaving the field (if the values are correct).
According
to the tradition accepted in the laser literature, the output of
radiation in the scheme is carried out to the right. The origin of the Z coordinate axis is located at the location of the high reflecting mirror. Mirrors and lens are considered thin.
View of the first page of the application.
Notations on the optical scheme: DTEM00 is the TEM00 mode diameter, DFULL is the diameter of the entire beam, ΘTEM00 is the TEM00 mode divergence, ΘFULL is the divergence of the entire beam.
By pressings and by holdings the buttons with the "<<" and ">>" signs, you can vary the parameter values up and down by the value specified in the "Step"
field. In this way, it is possible to select a laser cavity with the
desired beam caustic. The results of changing parameters are
immediately displayed on the scheme.
ADVICE. If it is not possible to find a lens with which the laser cavity is stable, go to the third page and find the stability zone by setting a wide range of optical power of the lens.
The indeterminacy of the result is indicated in the application using the abbreviation "NAN" (not a number).
You can read about the calculation algorithms in the "Calculation methods" section.
The second page ("Beam") displays a plot of the caustic calculated on the previous page for the TEM00 mode and the entire beam. There you can also calculate the field sizes and power focusing N in any section inside the laser cavity by entering the coordinate in the "Z" field. You can read about the calculation algorithms in the "Calculation methods" section.
View of the second page of the application.
On the third page,
the dependence of the divergence in the selected range of the optical
power of the lens is calculated. The optical power range of the lens is
set by its boundaries in the "P1" and "P2" fields. You can also calculate the divergence for a specific lens optical power value by entering this value in the "P" field.
View of the third page of the application.
You can read about the calculation algorithms in the "Calculation methods" section.
On the fourth page, plots of the dependence of the aperture loss of the TEM00 - TEM22 Hermite-Gauss modes
on the optical power of the lens can be calculated. The optical
power range of the lens for the loss calculating is the same as
for calculating of the divergence. To change it, you need to return to
the "Divergence" page. The
modes for which you want to see a plot are selected from the list on
the left (marked with a tick by clicking the left mouse button).

View of the fourth page of the application.
You can view the distribution of loss by TEM00 - TEM22 modes for a specific value of the optical power of the lens after setting this value in the "P" field and clicking the "Loss distribution" button. After clicking the button, the following window will be displayed:

View of the loss distribution window.
To return back, close this window with the "Close" button (or select the "Quit" item from the "File" menu of the window).
You can read about the calculation algorithms in the "Calculation methods" section.
When
you exit the application, the geometric settings of the application are
saved (i.e., the application font size, the application position on the screen,
the application window size), as well as the settings for the accuracy
of viewing results and for exporting plots points to text, optical
scheme parameters, and paths to recent files. They are loaded the next
time you start the application and you can continue to work on their
base. Moreover, sessions and settings files can be used, as described
below.
Features that available through the application menu
Working with sessions. The
session contains all the application settings, except for geometric
ones (i.e. the application font size, the application position on the
screen, the application window size); includes settings for the laser
cavity parameters, settings for the accuracy of viewing results and for
exporting plots points to text, paths to the latest files. Sessions can
be saved and loaded. You can start the default session with the initial
settings. Working with sessions is carried out using the "File/Sessions" menu.
Features that available through the "Settings" item. Using the sub-items of this menu item, it's possible to change the font
size of the application, the accuracy of viewing of the results, the
settings for exporting plots points to text; also, it's possible to save to a
file, read from a file and reset to the default state all these
settings.
Saving pictures. You can save pictures displayed on the pages of the application (scheme, plots) to files in vector (pdf and svg files) and raster (png and jpeg files) format using the sub-items of the application "File/Save picture" menu,
selecting a folder, file extension and entering the file name in the
dialog box that opens. The picture that is on the current page is
saved. Also, pictures can be copied to the clipboard in raster format by
means of the menu called by the mouse right
button clicking in the picture area. For plots, it is
possible to save points in the form of a table of values to a text
file by means of the main menu and to the clipboard - using the menu
called by the mouse right button clicking in the plot area. The "Loss distribution"
window has similar possibilities, except for working with a table of
values (the values are displayed in the window itself on the right).
Printing pictures. The picture (scheme or plot) displayed on the current page of the application can be printed. The menu item "File/Print..." is used for this aim. Selecting this item opens a dialog box with a preview and print settings. If necessary, do print preferences using this dialog box and click the printer icon at the top right. Similar functionality is implemented for the "Loss distribution" window.
Brief report generation. Using the application "File/Brief report..." menu item, it's possible to create a report that includes the laser cavity optical scheme, its parameters and the results of calculating for the beam as a whole and for the TEM00
mode (size of field in each optical element, divergence). You can
add your comment to the report. The report is saved as a pdf file. If desired, it can be send to a printer from third-party applications for working with pdf files (Adobe Reader, Foxit Reader, etc.).