An apparatus (10) includes a digital micromirror device (16) disposed within a housing (11) that has an opening (13) hermetically sealed by a lid (17). The lid includes a radiation transmissive window (22) with peripheral edges fixedly coupled by an annular sealing section (23) to a metal frame (21). The sealing section engages a frame surface oxidized in a wet nitrogen furnace. The sealing section melts at a temperature lower than the window or frame. The sealing section includes two center rings (151, 152) made of sealing glass that are respectively bonded to the window and frame and to each other. The sealing section also includes inner and outer rings (152, 157, 158) made of sealing glass and disposed on opposite sides of the center rings to protect the center rings from environmental factors.