During a double-slit experiment, you have the option of using either a green laser or a blue laser for your light source. Given the same configuration of your equipment, which one of these lasers would produce an interference pattern that has the largest spacing between bright spots?

Green laser

Explanation:

In the double slit experiment, the distance between two consecutive bright spots or two consecutive dark spots is defined as the fringe width

We are assuming that the two slits are on a vertical line

The formula for fringe width is (D * wavelength of light) : d

where D is the distance from the slit to the screen where the interference pattern is observed

d is the distance between the two slits

As it is given that both lasers have same configurations which means they both have same value of D and d

∴ Fringe width directly depends on the wavelength of the light

As green laser has more wavelength when compared to blue laser

∴ Green laser would produce an interference pattern that has the largest spacing between bright spots when compared to blue laser