Design Spectrophotometer for Blocking the $2^{nd}$ diffracted Light

2차 회절광 차단을 위한 분광 광도계 설계

Stray light is the light except the light of the analytic wavelength and the source of measurement error of absorbance. Some experimental results showed that diffractive grating is the major factor of stray light in spectrophotometer. Through the ray tracing with the software tool, classified the paths of the diffractive light from grating and found the range of wavelength which reach the exit slit. The quantity of the stray light(0.025％) is more than the minimum limit of stray light(0.01％) of the single monochromator. A novel optical layout design method, which prevent the reflected rays entering the diffractive grating is proposed.