An interferometer system to generate an interference signal of a surface of a sample comprising: a broadband illuminator to provide a broadband illumination beam; a beam splitter to split the broadband illumination beam in a reference beam for reflection on a reference reflector and a measurement beam for reflection on the surface of the sample; and a detector to receive an interference radiation intensity created between the reference beam reflected from the reference reflector and the reflected measurement beam from the surface of the sample to generate an interference signal; wherein the interferometer system further comprises: a continuous variable broadband reflector in the beam splitter to adjust the broadband radiation intensity balance between the measurement beam and the reference beam, a scanner constructed and arranged to scan the surface of the sample with respect to the measurement beam in a direction substantially perpendicular to the surface over a scanning distance while measuring the scanning distance generating a scanning distance signal; and a processor configured to receive the interference signal representing the interference radiation intensity during the scan from the detector and the scanning distance signal from the scanner and combining both to a correlogram displaying an interference radiation intensity as a function of the scanning distance, wherein the continuous variable broadband reflector comprises: a temperature dependent reflector of which a reflectivity is dependent on the temperature; and a temperature adjuster to adjust the temperature of the temperature dependent reflector to adjust the reflectivity of the temperature dependent reflector. a broadband illuminator to provide a broadband illumination beam; a beam splitter to split the broadband illumination beam in a reference beam for reflection on a reference reflector and a measurement beam for reflection on the surface of the sample; and a detector to receive an interference radiation intensity created between the reference beam reflected from the reference reflector and the reflected measurement beam from the surface of the sample to generate an interference signal; wherein the interferometer system further comprises: a continuous variable broadband reflector in the beam splitter to adjust the broadband radiation intensity balance between the measurement beam and the reference beam, a scanner constructed and arranged to scan the surface of the sample with respect to the measurement beam in a direction substantially perpendicular to the surface over a scanning distance while measuring the scanning distance generating a scanning distance signal; and a processor configured to receive the interference signal representing the interference radiation intensity during the scan from the detector and the scanning distance signal from the scanner and combining both to a correlogram displaying an interference radiation intensity as a function of the scanning distance, a continuous variable broadband reflector in the beam splitter to adjust the broadband radiation intensity balance between the measurement beam and the reference beam, a scanner constructed and arranged to scan the surface of the sample with respect to the measurement beam in a direction substantially perpendicular to the surface over a scanning distance while measuring the scanning distance generating a scanning distance signal; and a processor configured to receive the interference signal representing the interference radiation intensity during the scan from the detector and the scanning distance signal from the scanner and combining both to a correlogram displaying an interference radiation intensity as a function of the scanning distance, wherein the continuous variable broadband reflector comprises: a temperature dependent reflector of which a reflectivity is dependent on the temperature; and a temperature adjuster to adjust the temperature of the temperature dependent reflector to adjust the reflectivity of the temperature dependent reflector. a temperature dependent reflector of which a reflectivity is dependent on the temperature; and a temperature adjuster to adjust the temperature of the temperature dependent reflector to adjust the reflectivity of the temperature dependent reflector.