A spectral feature selection apparatus includes a dispersive optical element arranged to interact with a pulsed light beam; three or more refractive optical elements arranged in a path of the pulsed light beam between the dispersive optical element and a pulsed optical source; and one or more actuation systems, each actuation system associated with a refractive optical element and configured to rotate the associated refractive optical element to thereby adjust a spectral feature of the pulsed light beam. At least one of the actuation systems is a rapid actuation system that includes a rapid actuator configured to rotate its associated refractive optical element about a rotation axis. The rapid actuator includes a rotary stepper motor having a rotation shaft that rotates about a shaft axis that is parallel with the rotation axis of the associated refractive optical element.

The present invention provides a measurement system of real-time spatially-resolved spectrum and time-resolved spectrum and a measurement module thereof. The measurement system includes an excitation light and a measurement module. The excitation light excites a fluorescent sample and the measurement module receives and analyzes fluorescence emitted by the fluorescent sample. The measurement module includes a single-photon linear scanner and a linear CCD spectrometer. The single-photon linear scanner selectively intercepts a light beam component of a multi-wavelength light beam that has a predetermined wavelength to generate a single-wavelength time-resolved signal, wherein the multi-wavelength light beam is generated by splitting the fluorescence. The linear CCD spectrometer receives the multi-wavelength light beam and generates a spatially-resolved full-spectrum fluorescence signal. With the implementation of the present invention, the spatially-resolved full-spectrum fluorescence signal and the single-wavelength time-resolved signal can be observed at the same time. Thus, the facility of a fluorescence spectrometer is improved.