Competitive waves with an optical path difference l = 2.1 μm arrive at a certain point in space.

Competitive waves with an optical path difference l = 2.1 μm arrive at a certain point in space. Amplification or attenuation of light waves will occur at this point if the wavelengths are equal to 600 nm

Δl = 2.1 μm = 2.1 * 10 ^ −6 m.
λ = 600 nm = 600 * 10 ^ −9 m.
k -?
For coherent waves, the amplification condition is: Δl = 2 * k * λ / 2, where k = 1, 2, 3, 4, .., λ is the wavelength. A pair of half waves must be embedded in the difference in travel.
For coherent waves, the attenuation condition is: Δl = (2 * k + 1) * λ / 2, where k = 1, 2, 3, 4, .., λ is the wavelength. A non-paired number of half waves must be invested in the difference of the course.
k = Δl / (λ / 2).
k = 2.1 * 10 ^ −6 m / 300 * 10 ^ −9 m = 7 – an unpaired number, which means that the waves will weaken at this point.
Answer: k = 7 is not a paired number, at the point there will be a weakening of waves