OpticsApplet v1.1  requires a Java 1.1 enabled browser that allows JavaScript to applet communication. It is available here for use in non-commercial educational endeavors.  

The Applet is best viewed using the "Full Screen" option in your browser.

General Applet Procedure:

  1. Click on the FULL SCREEN command at the top of the browser control panel.
  2. You should notice when the applet loads that the screen area is black with a yellow horizontal line dividing the dark area into two equal halves. This area is the optics bench active area. The yellow line is the principal axis for any lens or mirror in the active area.
  3. Place the mouse cursor in the dark area of the applet. Notice the yellow-coordinate box that appears in the lower left-hand corner of the screen. The coordinate box indicates the position of the cursor position on the screen. This in turn can locate the position of any object or image placed on the optics bench.
  4. Move the cursor on the screen and determine the maximum and minimum X and Y coordinate values.
  5. X-Coordinate Y-Coordinate

    Maximum Value _____________ _______________

    Minimum Value _____________ _______________

  6. Notice at the top of the applet screen are menu buttons to select "BEAM", "OBJECT", "SOURCE", or "CLEAR ALL". At the bottom of the applet screen are menu buttons for "LENS", "MIRROR", "APERATURE", or "CLEAR ACTIVE".
  7. Begin by selecting "BEAM". To do this press the beam button and then move the cursor into the dark area of the screen and click where you want to place the beam. A beam is a source of parallel rays.
  8. Place your cursor in the green circle of the beam to make this "ACTIVE". Notice the two white spots near the circle. Place the mouse on these two white circles and describe the control you have over the beam for these two points as you "drag" the mouse about.




9. Press "CLEAR ALL". Now select "SOURCE" from the upper applet menu and click the mouse with the cursor in the dark area of the applet. Describe the emitted ray pattern from the source.


  1. Place the cursor on the white spot on the upper beam from the source. Drag the mouse and state how this changes the rays from the beam.


Can the position of the "source" be moved on the screen? __________________

How? __________________________________________________________________________

11. Press "CLEAR ALL". Now Select "OBJECT" and click the mouse with the cursor in the dark area of the screen. Describe what is placed on the screen. ___________________________

Can this "object" be moved on the screen? __________ Can you change the height of the Object? __________ . Where do you have to click on the object to move it or change its size? ___________________________. How would you measure the vertical height of the "object" you created on the optics bench? 


12. Press "CLEAR ALL". Now select from the bottom applet menu the lens by clicking on the LENS button. Now move the mouse cursor into the applet dark active area and click the left mouse button once. What type of lens is seen on the screen? ___________________. How are you able to move the lens horizontally on the screen? _________________________

Does the applet show a vertical axis for the lens? __________________What color is it? ______

Does the applet show the real and virtual focal points for the lens. _________ . How would you measure the focal length of the lens?


Are you able to make the focal length greater or smaller? _____

How? ___________________________________________________________________________________

Describe what happens when your mouse drags the left focal point to the far right side of the lens.


Does the applet allow you to change the lens type from convex to concave? ____________

Intro to Optics Bench
Lens Lab Worksheet
Curved Mirror Lab Worksheet
Plane Mirror Lab Worksheet