**Multiterawatt Hybrid (Solid/Gas) Femtosecond Systems in the Visible**

Leonid D. Mikheev and Valery F. Losev

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/63972

#### **Abstract**

A novel hybrid (solid/gas) approach to the development of femtosecond high‐intensity laser systems operating in the visible is presented in this chapter. Behind this ap‐ proach is a combination of a solid‐state front end relying on widespread and highly developed techniques for femtosecond pulse generation in the near infrared with a photochemically driven boosting amplifier operating in the visible spectral range. Historical background of developing photochemically pumped gas lasers on broad bandwidth electronic transitions in molecules and physical principles of their opera‐ tion are briefly summarized as well. The architecture and the design issues of the hybrid femtosecond systems relying on the amplification of the second harmonic of Ti:sapphire front ends in the photodissociation XeF(C‐A) power‐boosting amplifiers driven by the VUV radiation from electron‐beam‐to‐VUV‐flash converters are described, as well as breakthrough results of proof‐of‐principle experiments demonstrating a high poten‐ tial of the hybrid approach. Wavelength scaling of laser‐matter interaction is shortly discussed to demonstrate advantages of shorter driver wavelengths for some applica‐ tions with main emphasis placed on recombination‐pumped soft X‐ray lasers.

**Keywords:** hybrid femtosecond systems, visible spectral range, photochemically driven laser media, laser-matter interaction
