The first firmly established product development of CryLaS GmbH is the High-Power Series. With comparatively low repetition rates of about 20 Hz to 100 Hz, the pulse energies here are much higher than those of the Q lasers developed later. The latter have more compact dimensions, both for the controller and the laser head, but unlike the High-Power series, they are not optimized by closed-loop control. NLO optics (conversion crystals) are installed in an airtight capsule, which convert the initially generated 1064 nm fundamental to frequency multiples, so that wavelengths from DUV to IR are available with these lasers:
- 213 nm
- 266 nm
- 355 nm
- 532 nm
- 1064 nm
A photodiode monitors the relative laser energy at the beam output during operation and passes this data to a closed loop control system. The diode currents are evaluated and ultimately serve as the basis for fast-acting temperature adjustments within the laser head. These always keep the noise of the laser power as low as possible in the optimum. Since heat is generated in the laser (when pumping the resonator), the closed loop serves to counteract this.
The 355 nm lasers of the High-Power model series are based on frequency conversion and combination. The microchip, consisting of an Nd:YAG as well as a Cr.YAG crystal bonded to it, is pumped with an 808 nm laser diode. The resulting fundamental wave of 1064 nm is guided into conversion crystals sealed off from the air and finally frequency tripled, resulting in an emission wavelength of 355 nm. Depending on the pump time, lasers with three different pulse energies from 70 µJ to 300 µJ can be realized. Since the wavelength is well absorbed by biological materials without destroying them extensively, lasers at 355 nm are well suited for cutting or dividing biological samples, such as cell structures. Therefore, the 355-HP series is mainly used in mass spectroscopy and microdissection. Their high pulse energy puts them in direct competition with the 337.1 nm nitrogen (N2) lasers also commonly used in these applications.