A fiber measurement device for measuring a physical quantity by a fiber and a method for shaping a pulse of electromagnetic radiation are disclosed. The fiber measurement device comprises an electromagnetic radiation source and an adjustment unit. The electromagnetic radiation source generates at least one pulse of electromagnetic radiation as primary electromagnetic radiation to be coupled into the fiber, and an adjustment unit. The adjustment unit, prior to, during or after application of the primary electromagnetic radiation to the fiber, adjusts a shape of the at least one pulse for at least partially compensating a deviation between a target shape and an actual shape of the at least one pulse.