Providing greater than 99.8% reflectivity for S and P polarization, Gires-Tournois Interferometer Mirrors are optical standing wave-resonators that are primarily used in chirping applications such as pulse compression. Units use partially reflective front surface and highly reflective back surface to generate chromatic dispersion. Available in 4 RoHS-compliant, 25.4 mm diameter models in wavelengths from 780–820 nm and 1020–1060 nm, mirrors feature group delay dispersion from -250 to -600 fs².