The intensity is given by the absolute value of the complex amplitude squared I ( x ) = Ψ Ψ Ψ Ψ ∗ ∗ = | Ψ Ψ | 2 = I 0 ( sin ⁡ ⁡ ( N k a x 2 L ) sin ⁡ ⁡ ( k a x 2 L ) ) 2 where Ψ Ψ ∗ ∗ denotes the complex conjugate of Ψ Ψ .