NCLR

Nederlands Centrum voor Laser Research (NCLR) B.V. was founded in 1989 as a joint venture of university and industry to research and develop advanced high power laser systems and their applications. NCLR is scientifically backed through the expertise of the University of Twente where laser research started back in the sixties. Close links also exist with other universities, research institutes and several industrial organisations. Some of its research projects are being financially supported by national and international science and technology funding programmes.

NCLR has taken the excimer laser technology researched by the University of Twente and developed the SIRIUS 1000, a 1 kW excimer laser operating at a wavelength of 308 nm and a repetition rate of 1 kHz. The short wavelength, high average power and high repetition rate makes this laser very useful for industrial scale material processing. Another advantage of the SIRIUS 1000 is the (relative) long pulse duration of around 200 ns which results in a very good laser beam quality. 

NCLR is collaborating with several industrial partners to apply this laser in several types of material processing, e.g., for hole drilling in (composite) materials used in aerospace industry. To obtain a high production speed, NCLR is investigating advanced parallel hole drilling techniques. With this method hundreds to thousands of holes can be drilled per second depending on size of the holes, thickness and type of material. An excellent balance between production speed and hole quality which is attributed, amongst others, to the pulse duration and the good beam quality of the SIRIUS 1000.

Solid state lasers have grown immensely in brightness since the operation of the first ruby laser and promise to do so again with the advent of diode lasers as a new pumping source. Diode lasers transfer the energy to the solid state material much more efficient then flashlamps allowing much higher average loading levels. Added advantages are the stability, reliability, and increased lifetime. These properties have also a beneficial influence on the beam quality produced by diode-laser pumped solid-state lasers. The output power of Nd:YAG systems is essentially limited by the fracture limit of the Nd:YAG crystals. Within this limit either a few pulses of high intensity or a lot of pulses with lower intensity can be produced. NCLR is using advanced concepts for realising a 40 W Nd:YAG laser operating at 1064 nm with a maximum pulse repetition rate of 1 kHz and an excellent beam quality. These properties allow the construction of compact and rugged laser systems, which can be used for, amongst others, range-finding, spectroscopy, lithography, materials processing, medical applications. The wavelength of the Nd:YAG laser is suitable for transport through fibers, which allows for flexible beam delivery systems. Furthermore, the high beam quality and high peak power allow for efficient generation of different wavelengths, thereby considerably enlarging the field of applications for this type of laser.

Another class of laser systems is formed by the free-electron laser (FEL). In this device, kinetic energy of electrons is converted into a coherent laser beam. The radiation wavelength is determined by the velocity of the electrons and, thus, virtually every wavelength can be generated by using an appropriate accelerator for the electrons. Advantages of the FEL are the continuous tunability, the high peak and average power and the high overall efficiency. NCLR is working together with the University of Twente on the development of a FEL which operates in the microwave part of the spectrum, thereby extending the available source capabilities in this spectral range. Applications for this source are investigated in collaboration with European industrial and institutional partners. For example, high resolution, high frequency (90 GHz or higher) radar systems require a high power amplifier with a relatively wide bandwidth. The requirements for such an amplifier can be fulfilled by the FEL. Other applications include microwave assisted (plasma) chemistry, microwave plasma material processing, focussed microwave heating and microwave UV/ozone production. The ozone production is important for steralisation of all kind of rooms varying from public places like schools and hospitals to airplanes.