Abstract: Some systems comprise a light source; a spectrometer; an optical scope that has a longitudinal axis and that includes a rotatable optical assembly, which is coupled to the light source and to the spectrometer; and an oscillating-drive device that is coupled to the optical scope. Also, the oscillating-drive device and the optical scope are configured such that the oscillating-drive device can oscillate the rotatable optical assembly of the optical scope through greater than 90° of rotation around the longitudinal axis of the optical scope. And some systems comprise an optical scope that includes a rotatable optical assembly and a spooling mechanism. The rotatable optical assembly includes one or more light-guiding components. Furthermore, the spooling mechanism is configured to wind or unwind the one or more light-guiding components when the rotatable optical assembly rotates.