• Traveling wave single crystal, four amplification stage configuration
• Energy conversion up to ~30-50%
• Angular tuning limited by crystal transparency range only
• Grating frequency selector
• Upgradability for pump energy, wavelength and pulse width
• Computer controlled operation throughout wavelength range
• Optional frequency mixers

TYPICAL TUNING OF TOPAS
PUMPED BY MODEL CPA-SERIES Ti:SAPPHIRE REGEN AMPS

TOPAS has attracted world-wide interest due it its flexibility, very large tuning range and the possibility of up-scaling to a high power output.

Different frequency mixing schemes allow for continuous tuning across the entire accessible wavelength range of 189 to 20 microns by simply entering a desired wavelength in a computer.

The TOPAS can be operated in both the fs and ps mode, or converted between them. Energy conversion up to 20-40% is possible in the fundamental. An important feature of TOPAS design is that it can be matched to pump sources with peak power ranging over an order of magnitude. There are no limitations for pulse repetition rate up to several kilohertz. The ability to vary repetition rate makes it easier to optimize performance.

TOPAS consists of a continuum generator, two preamplifiers, and a power amplifier. All of these stages are geometrically arranged using a single nonlinear crystal. The power amplifier uses >90% of the pump energy and is adjusted for high conversion efficiency along with the beam quality and duration of the converted pulses.

To achieve high reproducibility of generated pulses, all the amplification stages are driven close to saturation. At each stage, the pump energies and intensities are adjusted for the particular pump pulse width and power used.