Gires-Tournois interferometer type negative dispersion mirrors for deep ultraviolet pulse compression.

Typical femtosecond pulse compression of deep ultraviolet radiation consists of prism or diffraction grating pair chirp compensation but, both techniques introduce higher-order dispersion, spatial-spectral beam distortion and poor transmission. While negatively chirped dielectric mirrors have been used to compress near infrared and visible pulses to <10 fs, there has been no extension of this technique below 300 nm. We demonstrate the use of Gires-Tournois interferometer (GTI) negative dispersion multilayer dielectric mirrors designed for pulse compression in the deep ultraviolet region. GTI mirror designs are more robust than chirped mirrors and, can provide sufficient bandwidth for the compression of sub-30-fs pulses in the UV wavelength range. Compression of a 5 nm (FWHM) pulse centered between 266 and 271 nm to 30 fs has been achieved with less pulse broadening due to high-order dispersion and no noticeable spatial deformation, thereby improving the resolution of ultrafast techniques used to study problems such as fast photochemical reaction dynamics.