Radius of curvature (ROC) determinations based on ROC-dependent optical conjugate positions

A test system for determining a radius of curvature (ROC) of a device under test (DUT), the test system comprising:

• a controller;
• and
• a memory on which is stored machine-readable instructions that when executed by the controller, cause the controller to:
• cause a relative position between a DUT location at which the DUT is positioned and a lens of optical components to vary, wherein varying the relative position causes conjugate images of a fiducial mark positioned on one of the optical components to be relayed through the optical components and from the DUT to an imager at varying levels of focus;
• determine a position of the DUT location with respect to the lens at which a conjugate image of the fiducial mark captured by the imager is in focus;
• and
• determine the ROC of the DUT based on an application of a correlation of ROC-dependent optical conjugate positions in the optical components induced by the ROC of the DUT from the determined position of the DUT location with respect to the lens.

A method of determining a radius of curvature (ROC) of a device under test (DUT), the method comprising:

• causing, by a controller, a relative position between a DUT location at which the DUT is positioned and a lens of optical components to vary, wherein varying the relative position causes conjugate images of a fiducial mark positioned on one of the optical components to be relayed through the optical components and from the DUT to an imager at varying levels of focus;
• determining, by the controller, a position of the DUT location with respect to the lens at which a conjugate image of the fiducial mark captured by the imager is in focus;
• and
• determining, by the controller, the ROC of the DUT based on an application of a correlation of ROC-dependent optical conjugate positions in the optical components induced by the ROC of the DUT from the determined position of the DUT location with respect to the lens.