A system, comprising: a coordinate measurement machine, CMM, comprising: a probe head having an auto exchange joint element of a probe autojoint connection; and a first coupling element of a free-space fiber optic coupling mounted to the probe head; wavelength detector and light source elements; CMM control circuitry; and a chromatic range sensor, CRS, optical probe comprising: an optical pen having a confocal optical path including at least a confocal aperture and a chromatically dispersive optics portion, the optical pen configured to focus different wavelengths at different distances along a measurement axis (MA, MA') proximate to a workpiece surface to be measured; a second coupling element of the free-space fiber coupling mounted to the CRS optical probe; and an auto exchange joint element of the probe autojoint connection which is attachable through the auto exchange joint element of the probe autojoint connection to the CMM, characterized in that one of the first and second coupling elements (871; 872) of the free-space fiber coupling includes a free-space lens system having a pair of lenses (852', 853') and a first fiber optic connector (809'; 809") which receives an end of a first fiber optic cable (812'; 812") including a first optical fiber, and the other of the first and second coupling elements (871; 872) of the free-space fiber coupling includes a second fiber optic connector (809"; 809') which receives an end of a second fiber optic cable including a second optical fiber, and the pair of lenses (852', 853') is configured to collimate light received via the first optical fiber of the first fiber optic cable (812'; 812") and focus the light into the second optical fiber of the second fiber optic cable. a coordinate measurement machine, CMM, comprising: a probe head having an auto exchange joint element of a probe autojoint connection; and a first coupling element of a free-space fiber optic coupling mounted to the probe head; a probe head having an auto exchange joint element of a probe autojoint connection; and a first coupling element of a free-space fiber optic coupling mounted to the probe head; wavelength detector and light source elements; CMM control circuitry; and a chromatic range sensor, CRS, optical probe comprising: an optical pen having a confocal optical path including at least a confocal aperture and a chromatically dispersive optics portion, the optical pen configured to focus different wavelengths at different distances along a measurement axis (MA, MA') proximate to a workpiece surface to be measured; a second coupling element of the free-space fiber coupling mounted to the CRS optical probe; and an auto exchange joint element of the probe autojoint connection which is attachable through the auto exchange joint element of the probe autojoint connection to the CMM, characterized in that one of the first and second coupling elements (871; 872) of the free-space fiber coupling includes a free-space lens system having a pair of lenses (852', 853') and a first fiber optic connector (809'; 809") which receives an end of a first fiber optic cable (812'; 812") including a first optical fiber, and the other of the first and second coupling elements (871; 872) of the free-space fiber coupling includes a second fiber optic connector (809"; 809') which receives an end of a second fiber optic cable including a second optical fiber, and the pair of lenses (852', 853') is configured to collimate light received via the first optical fiber of the first fiber optic cable (812'; 812") and focus the light into the second optical fiber of the second fiber optic cable. an optical pen having a confocal optical path including at least a confocal aperture and a chromatically dispersive optics portion, the optical pen configured to focus different wavelengths at different distances along a measurement axis (MA, MA') proximate to a workpiece surface to be measured; a second coupling element of the free-space fiber coupling mounted to the CRS optical probe; and an auto exchange joint element of the probe autojoint connection which is attachable through the auto exchange joint element of the probe autojoint connection to the CMM, characterized in that one of the first and second coupling elements (871; 872) of the free-space fiber coupling includes a free-space lens system having a pair of lenses (852', 853') and a first fiber optic connector (809'; 809") which receives an end of a first fiber optic cable (812'; 812") including a first optical fiber, and the other of the first and second coupling elements (871; 872) of the free-space fiber coupling includes a second fiber optic connector (809"; 809') which receives an end of a second fiber optic cable including a second optical fiber, and the pair of lenses (852', 853') is configured to collimate light received via the first optical fiber of the first fiber optic cable (812'; 812") and focus the light into the second optical fiber of the second fiber optic cable.