Optical path diagram.

From the light source (LED), the light line passes the fast filter wheel (F1) and lens (L1) and reaches the samples. The light focuses on and illuminates the samples through an objective (OL). PM is the pulse modulator, which controls the motored stage step by step. The light beam is adjusted through a tube lens (TL) and beam splitter (BS). A line of the light illuminates the sample region in the same position as the resulting emission light through a diorchic mirror (DM) and the imaging spectroscope, and finally reaches the CCD camera (CM).