**2. Module structure**

Each software tool is developed under the following structure:


The **theoretical background** module introduces the student to the optical phenomenon. Then, by using the **simulation** module, the user can make simulations of the phenomenon using the power and flexibility of MATLAB. Interaction and/or comparison with real, physical experiments can be achieved through the **laboratory experimentation** module. At any time, the user can get interactive help on each module.

<sup>1</sup> The list of covered optical phenomena is being extended, to include more optical topics such as Theory of Color, Geometrical Optics and Optical Fibers, among others

in Optics 3

A Contribution to Virtual Experimentation in Optics 359

The intensity of the computed diffraction pattern is shown on the right-side image frame in Fig. 2 (a). Such diffraction pattern can be sent to a printer, or stored as an image file on the PC for further processing. By clicking on Cross section, a profile of the intensity diffraction

(b) Cross-section of the computed

diffraction pattern

pattern can be plotted, as shown in Fig. 2 (b).

(a) Fraunhofer pattern for 5 vertical slits illuminated with

**3.3 Laboratory experimentation module**

output screen is stored by a video camera.

**4. Computer generated holograms tool**

experiment module shown in Fig. 4.

• The object does not need to exist.

Fig. 2. Example of far-field diffraction pattern computed for 5 vertical slits

of the 60's (Brown & Lohmann, 1966). Some essential aspects of CGHs are:

One of the most interesting features of the tool is the possibility to compare simulations with real experiments. Fig. 3 shows the basic laboratory setup. A collimated He-Ne laser illuminates the object (aperture), and the corresponding diffraction pattern projected on the

Images captured by the video camera can be stored and processed by the laboratory

The idea of using computers to define and generate holograms was proposed by the middle

• The construction of the hologram is done away from the usual diffracting objects: the image is defined, and the diffracting object that produces such an image is then calculated.

red light
