Configurable retro-reflective sensor system for the improved characterization of the properties of a sample

A retroreflector-based sensor system for optical characterisation of a sample, having a transmitter for irradiating the sample which is positioned in the transmitter beam path, a retroflector which is positioned behind the sample in the transmitter beam path such that it reflects radiation in the transmitter beam path coming from the sample and incident thereon in the receiving beam path back onto the sample,

• the transmitter, the sample, and the retroreflector being positioned such that radiation reflected back from the retroreflector in the receiving beam path is again incident on the sample and is reflected back from the latter in the direction towards the transmitter, and
• a receiver which is positioned in the receiving beam path such that it detects radiation reflected back from the retroreflector, incident again on the sample and reflected back from the latter, in the direction towards the transmitter,
• from the radiation detected by the receiver, measured values being obtainable and evaluatable for optical characterisation of the sample, and
• one or more configuration means being provided, by means of which improved obtaining and/or evaluation of the measured values is/are possible, for improved optical characterisation of the sample.