where the wavelength of light (λ) diffracted at a measured angle (θ) can be calculated. The grating order is n (here n = 1), and
the grating line spacing d for a 1000 line/mm grating is 1.0 ×10−6 m. According to eq 1, orange light at 589 nm
(λ = 0.589 ×10−6 m) is diffracted at θ = 36°