1. The problem statement, all variables and given/known data A laser with wavelength d/8 is shining light on a double slit with slit separation d. This results in an interference pattern on a screen a distance L away from the slits. We wish to shine a second laser, with a different wavelength, through the same slits. What is the wavelength (lambda_2) of the second laser that would place its second maximum at the same location as the fourth minimum of the first laser? Express your answer in terms of d 2. Relevant equations I have (dsin(theta)) = 2(lambda_1) and dsin(theta)= (9/2)(lambda_2) 3. The attempt at a solution I set the two equations equal to each other, and solve for lambda_2 and get (2/9)dsin(theta), but then it said the answer does not depend on theta.. so I just guessed and put (2/9)d and it said I was off by a multiplicative factor. basically, I'm confused and do not know how to go about solving this problem. please help!
I have (dsin(theta)) = 2(lambda_1) and dsin(theta)= (9/2)(lambda_2) Check this. Second maximum of second laser and fourth minimum of the first laser