Laser processing system, object mount and laser processing method

A processing system comprises a common base 53, an object mount 101 configured to hold an object for inspection or processing, at least one aperture plate provided on the object mount, wherein the aperture plate has at least one aperture, a laser device 15 mounted on the common base and configured to scan a laser beam 17 across a scan region 13, a transport device 103 configured to displace the object mount relative to the common base from a first position to a second position, wherein, when the object mount is in the first position, the object and the at least one aperture are positioned within the scan region of the laser device; at least one light guide provided on the object mount, wherein the light guide has an input port provided by the at least one aperture, and an output port; and at least one light detector 151 mounted at a fixed position relative to the common base and configured to detect light emerging from the output port of the light guide.