The arrangement for examining microscope preparations with a scanning microscope comprises a laser (1) and an optical means (12) which images the light generated by the laser (1) onto a specimen (13) that is to be examined. Provided between the laser (1) and the optical means (12) is an optical component (3, 20) that spectrally spreads, with a single pass, the light generated by the laser (1). The optical component (3, 20) is made of photonic band-gap material. It is particularly advantageous if the photonic band-gap material is configured as a light-guiding fiber (20).