Based on CryLaS’ first product development, the DSS1064 high-power laser, an entire product series has been developed. This operates at low pulse repetition rates of 20 Hz to about 100 Hz and, in terms of controller and laser head footprint, is less compact than the Q-Laser series developed later. In return, the high-power lasers offer a higher pulse energy level in compensation. Inside an sealed capsule are NLO crystals that generate frequency multiples of the fundamental wavelength of 1064 nm. Frequency doubling to quintupling finally results in a broadband spectrum of laser wavelengths that can be generated by means of this concept:
- 213 nm
- 266 nm
- 355 nm
- 532 nm
- 1064 nm
Furthermore, the almost complete absence of noise in this type of laser is ensured by a closed control loop. The temperature inside the laser head, which is always changing due to external influences or heat generation inside the resonator, is adjusted according to a photodiode signal. This monitors the intensity of the emitted laser radiation live. Thus, the laser is always operated at its optimum, which keeps the noise of the laser power low.
The 266 nm lasers of the high-power model series are based on frequency conversion, more precisely on frequency quadrupling of the 1064 nm fundamental wavelength by non-linear optics. The fundamental is generated by pumping a microchip with a laser diode (808 nm). The chip itself consists of a Nd:YAG crystal and a saturable absorber (Cr:YAG). The infrared laser beam is passed through two conversion crystals in sequence so that finally 266 nm can be emitted. This wavelength has a high photon energy of about 4.6 eV. This makes it ideal for fluorescence or photoluminescence analysis of semiconductors or other materials where high energies are needed for excitation, ionization or sublimation. This type of laser is used for ablation and mass spectrometry.