The Shack-Hartman wavefront sensor is a common metrology tool in the field of laser, adaptive optics and astronomy. However, this technique is still scarcely used in optics and optical system metrology. With the development of manufacturing techniques and the increasing need for optical characterization in the industry, the Shack-Hartmann wavefront sensor emerges as an efficient complementary tool to the well-established Fizeau interferometry for optical system metrology. Moreover, the raise of smart vehicles equipped with optical sensors and augmented reality, the optical characterization of glass and transparent flat materials becomes an issue that can be addressed with Shack-Hartmann sensors. Aberration measurements of challenging optics will be presented such as optical filters, thin flat optics, aspheric lenses and large optical assemblies.

We have studied and developed a compact nanosecond laser system dedicated to the ignition of aeronautic combustion engines. This system is based on a nanosecond microchip laser delivering 6 μJ nanosecond pulses, which are amplified in two successive stages. The first stage is based on an Ytterbium doped fiber amplifier (YDFA) working in a quasi-continuous-wave (QCW) regime. Pumped at 1 kHz repetition rate, it delivers TEM00 and linearly polarized nanosecond pulses centered at 1064 nm with energies up to 350 μJ. These results are in very good agreement with the model we specially designed for a pulsed QCW pump regime. The second amplification stage is based on a compact Nd:YAG double-pass amplifier pumped by a 400 W peak power QCW diode centered at λ = 808 nm and coupled to a 800 μm core multimode fiber. At 10 Hz repetition rate, this system amplifies the pulse delivered by the YDFA up to 11 mJ while preserving its beam profile, polarization ratio, and pulse duration. Finally, we demonstrate that this compact nanosecond system can ignite an experimental combustion chamber.

No abstract

No abstract