Development of Ultrashort Pulsed VUV Laser and its Applications

Vacuum ultraviolet (VUV) laser systems for advanced applications such as micro and precise processing and photochemical reactions have been developed. We have been constructing a VUVMOPA system to generate output energy of sub-mJ with a pulse width of sub-picosecond at the wavelength of 126 nm. A VUV seed pulse, generated by the 7th harmonics of a 882 nm Ti:Sapphire (TiS) laser was amplified by the Ar2 medium generated from an optical-field-induced ionization of Ar plasma pumped by the TiS laser. We achieved an amplification of 126 nm seed pulse by a factor of 2.6. Recently, we introduced a new 800 nm TiS laser. This laser was synchronized with the 882 nm TiS laser and the delay between these outputs was controllable. We also developed a photostimulated desorption spectroscopy method for surface analysis. A tunable incoherent VUV radiation obtained from a laser induced plasma was irradiated the samples and then desorbed species were analyzed by mass spectroscopy. This method enables analysis without sample heating and damaging.