The behavior of electrical circuits can be elegantly modeled as time-invariant systems (LTI systems). In electrical circuits, we are interested in knowing how the system behaves in time.
On the other side, with spectrophotometers working on steady-state conditions —time is irrelevant as nothing changes with time—, we are interested in the response of the equipment with wavelength (frequency, wavenumber).
Is it possible to describe a spectrophotometer as we do with LTI systems but changing time for wavelength?
Your feedback will be most welcome!