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OPAs

Light Conversion TOPAS

The TOPAS is a high-performance OPA which provides tunable output for femtosecond and picosecond laser pulses. Pumped by either Nd:YAG or Ti:Sapphire lasers, the TOPAS has been the best selling OPA since 1993.

  • 189nm to 20000nm tuning range
  • >30% energy conversion
  • Grating frequency selector
  • Near bandwidth and diffraction limited output
  • Pump energy, wavelength & pulsewidth extension upgrades
  • Computer controlled operation
  • Optional frequency mixers
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TOPAS 355 Specifications

Efficient, realiable and reproducible

The TOPAS features the best performance available on the world market during the last years, being the best selling device since 1995. It has attracted much fundamental and technological interest from the very beginning because of the flexibility of its optical scheme, extremely large tuning range, and the possibility of scaling up to a high-power output. the TOPAS can be easily adopted to be driven by a variety of laser systems, with pulsewidths ranging from 25 fs to 50 ps.

Design and principles of operation

The TOPAS consists of an independently pumped superfluorescence generator, three preamplifiers, and power amplifier. All these stages are geometrically arranged using a single nonlinear crystal. The seed signal is produced in low-energy preamplifiers, that are optimized for the best spectral and spatial filtering properties. 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 to saturation. At each stage, the pump energies and intensities are adjusted for the particular pump pulsewidth and power used.

Wavelength tuning

The tuning range of the TOPAS is restricted mainly by the pump wavelength and IR-absorption edge of the particular nonlinear crystal (BBO or LBO). This range is notably extended by the frequency up- and down-conversion of the the TOPAS output. Different frequency mixing schemes allow for continuous tuning across the whole accessible wavelength range and for generation of several synchronous pulses at different wavelengths.

The operation of the TOPAS has been tested when pumped with 200-fs and 1-ps second-harmonic pulses of Nd:glass laser, 30-ps third-harmonic pulses of Nd:YAG laser, 25-fs to 3-ps fundamental and 1-2.5 ps second-harmonic pulses of Ti:saphire laser. In all the cases energy conversion into the parametric radiation up to 20-40% was achieved. An important feature of the TOPAS design is that it can be matched to pump sources with peak power ranging over orders of magnitude. The minimum 150 fs pump pulse energy ensuring >5% parametric conversion is around 150 œJ. There are no limitations for pulse repetition rate up to several kilohertz.

Accessories

  • Frequency doubling and mixing Options
  • Deep-UV and mid-IR wavelength extension
  • Narrow-bandwidth generation
  • Wavelength separators
  • Polarisation control unit

We can also supply nanosecond OPOs