aqa physics syllabus(what does this mean)

In my syllabus it says:
"Requirements of two source and single source double-slit systems for the the production of fringes"
Does the single source mean, that the light consists of one wavelength, and does the double source, mean its from white light (more then one wavelength), or am I completely on the wrong lines.

Thanks

Reply 1

trance addict

coherence and wavelength, and principles of superposition.. more along the lines of that

Reply 2

zafaru123

the things you mentioned are already in the specification. I think it refers to 2 methods of producing fringes. When it says 2 sources, could this be from two lasers or something.

Reply 3

trance addict

oh

light pointed at a single slit reuqires two double slits in front to produce a pattern if the light is from a monochromatic source. the reason for this is the light is not in phase, therefore not coherent, so the single slit is required to do this

for laser light, the light is already co herent, so just a double slit setup is required