Singlet solution

Double-click on the OSLO icon to run the program.
Click on File >>New in the main window, then select Catalog Lens in the dialog box. Leave the magnification at its default value (0.0). Enter the name lasrcom1 for the file name, and click OK to dismiss the dialog.
The Catalog Lens Database window appears in front of the main window. Make sure the name shown in the Catalog cell is "MG_POS." If not, click on this cell and select MG_POS from the pop-up menu that is displayed.
Click on the box in the range control area of the window next to "Central Efl". Type the value 60 and press ENTER. Click the range field and set the value to 10. Click on the box next to "Central Dia," type the value 30, and press ENTER. Click the range field and set the value to 5. Use DOWN ARROW to move the selection in the lens list down to the lens 01LPX125 (watch the message area below the drawing). At this point, the Catalog Lens Database window should look like the one in the figure below.

When you have confirmed this, click OK in the Catalog Lens Database window. The window closes and you see the element 01LPX125 entered in the Surface Data Spreadsheet. The lens identification (lid) field in the upper left corner of the spreadsheet will originally be set to "no name". Change this to "Laser communications system". Then click on Draw On to enable the Autodraw window.
Click on the button at the right-hand end of the wavelengths field, which will originally have an asterisk in it. This will bring up the Wavelengths spreadsheet. Since this is to be a monochromatic system, you should delete wavelengths 2 and 3, and set wavelength 1 to 0.6328 micrometers. To do this, click the row button for wavelength 2, then the row button for wavelength 3. This will select the range. Then click on the scissors icon on the toolbar to delete the rows (or press the DELETE key). Then select the wavelength 1 field, which will become a black box with a narrow outline. This means that the field has an optional list that supports it. You can either type in a value, or click again on the field to pop up the list. Assuming that you click on the field (or press spacebar), the wavelengths list will appear as shown below.

Select the Helium-neon 0.6328 wavelength, then click OK twice (not double-click) to first enter the wavelength and then dismiss the wavelengths spreadsheet. You will return to the surface data spreadsheet, which should now appear as follows:

Notice that the radii of curvature are not shown, the thickness and glass buttons are replaced by an F, and the glass is marked FIXED. This is because you are looking at a catalog lens in group mode, and these are data that cannot be changed by the user. If you want to see the actual data, click Srf in the View field in the top line of the spreadsheet. You can remove the fixed designation by clicking on the radius button for surface 1 and selecting Ungroup.
The Autodraw window will show a picture of the lens, as shown below. Note that the entrance beam radius has been set to the aperture radius of the lens, and that a paraxial height solve has been placed on surface 2, by default. You can see this by using the arrow keys to highlight the options button in the thickness field for surface 2. You will see the command "PY 0" appear in the command line, which indicates a paraxial height solve.

Now, the lens is set up and the performance can be analyzed. A spot diagram will provide a general indication of the image quality. You can carry out an spd analysis using either text or graphics output. First, examine the graphics output by using the Calculate >> Display Spot Diagram command, using the default values given in the dialog box. The following report graphics screen will appear in the current graphics window. The display shows that the geometrical spot size is 0.6073mm, much too large to be useful.

Find the optimum focus for this lens. To do this, click Calculate >> Spot Size Analysis. In the dialog box, select Yes in the Find best focus field, then click OK to dismiss the box. The text window will show the spot size analysis, including the best focus position, -2.975853. You can also find the best focus position by clicking Optimize, Autofocus or clicking the SHIFT+F12 icon. The present method is designed to show you some additional ways to use the program.

Click on this number in the text window. This will produce a message in the main window showing the number to full internal precision, along with its location (a1) in the spreadsheet buffer (you might have a different location in your buffer). You can refer to this number in expressions by its symbolic notation.

Select the thickness SmartCell of surface 3 in the surface data editor. In this cell, enter a1. Note that the number is entered in the cell with full numeric precision. This cell, the thickness of the image surface, is interpreted as a focus shift in OSLO. That, is, the final image surface is located a distance equal to the sum of the thicknesses on the next-to-last and the last surfaces.
To update the spot diagram for the new information, double-click on the graphics window (or click the update icon in the graphics window). The analysis is automatically updated to reflect the new focus position. The geometrical spot size is 0.2036mm, much better than before, but still not acceptable.