Profile: Tower Optical Corp. is a manufacturer and producer of precision optics, assemblies and lasers. We are an ISO 9001:2000 certified company. Our product line includes waveplates & retarders, prisms, beamsplitters, lenses, windows, mirrors, transmission flats and camera couplers. Our 10 mm Zero order waveplates provide users with a crystal quartz retarder with a clear aperture of 8 mm. These waveplates are air spaced, having a stainless steel spacer between two crystal quartz plates that form the zero order capability. The zero order waveplates are far less sensitive to temperature variations. Our precision optical flats are fused silica optical components that are used as a reference against which the flatness of an unknown surface can be determined.