An end-effector for a surgical robot system may include an end-effector body and an optical sub-assembly. The optical sub-assembly may include a housing coupled to the end-effector body, the housing including a threaded portion. The optical sub-assembly may further include a window that is transparent to a predetermined range of light radiation wavelengths. The optical sub-assembly may further include a gasket disposed between the housing and the window. The optical sub-assembly may further include a threaded ring disposed over the window and threadedly engaging the threaded portion of the housing, the threaded ring compressing the gasket between the window and the housing to form a seal between the window and the housing. The optical sub-assembly may further include a light emitter configured to emit light in the predetermined range of light radiation wavelengths through the window.
