The theta-SE is a push-button spectroscopic ellipsometer for characterising thin film uniformity. For many applications, optical properties are desired at specific wavelengths. For example, the semiconductor industry is interested in lithography which requires ellipsometry measurements in the UV region (157 nm, 193 nm, 248 nm etc.). The display industry is interested in the visible spectrum. Optical coatings require measurement at their design wavelengths, whether at visible, near infrared or even mid-infrared wavelengths. The theta-SE covers the spectral range from 400–1000 nm.