A spectral imaging device (12) includes an image sensor (28), an illumination source (14), a refractive, optical element (24A), a mover assembly (24C) (29), and a control system (30). The image sensor (28) acquires data to construct a two-dimensional spectral image (13A) during a data acquisition time (346). The illumination source (14) generates an illumination beam (16) that illuminates the sample (10) to create a modified beam (16I) that follows a beam path (16B) from the sample (10) to the image sensor (28). During the data acquisition time (346), the control system (30) controls the illumination source (14) to generate the illumination beam (16), and controls the image sensor (28) to capture the data. Further, during the data acquisition time (346), an effective optical path segment (45) of the beam path (16B) is modulated.