The present disclosure relates to the field of optical systems. The envisaged multi-scan optical system is compact and stable. The system comprises an excitation source, a hydra fiber cable, a wavelength selector, an optical element, and a detector. The excitation source is configured to emit composite light. The hydra fiber cable has a head and a plurality of tentacles, and is configured to receive the composite light via a second lens. The plurality of tentacles is configured to emit the composite light towards the wavelength selector which includes a plurality of optical slits (s1-s8) and a plurality of shutters. The wavelength selector is configured to selectively collect and filter the composite light directed by a first lens and the plurality of tentacles by means of the plurality of shutters. The detector is configured to detect the plurality of spectral line scans reflected by the optical element for spectrometric analysis.