For are a few applets for you to play with
🍏 Slit: http://ngsir.netfirms.com/englishhtm/Diffraction.htm
🍏 Obstacle: http://ngsir.netfirms.com/englishhtm/Diffraction2.htm
🍏 Corner: http://ngsir.netfirms.com/englishhtm/Diffraction3.htm

For are a few applets for you to play with
🍏 Slit: http://ngsir.netfirms.com/englishhtm/Diffraction.htm
🍏 Obstacle: http://ngsir.netfirms.com/englishhtm/Diffraction2.htm
🍏 Corner: http://ngsir.netfirms.com/englishhtm/Diffraction3.htm