An apparatus includes a pulsed laser source that produces a pulsed laser beam at an input repetition rate and an input pulse power; a passive pulse splitter that receives the pulsed laser beam and outputs a signal including a plurality of sub-pulses for each input pulse of the pulsed laser beam, where the sub-pulses have a repetition rate that is greater than the input repetition rate and at least two of the sub-pulses have power less than the input pulse power; a sample accommodating structure configured to accommodate a sample placed in the path of a sample beam that is formed from the beam that exits the pulse splitter; and a detector that receives a signal of interest emitted from a sample accommodated by the sample accommodating structure based on the incident sample beam.