Abstract
To meet the ever-increasing demands of high resolution and versatility of microprocessing technology, diffractive optical elements (DOEs) are used to get the desired focal pattern [1]. The simplest phase DOE is a diffractive lens (DL). The focal length of a DL is given by f=fo λo/λ being fo the focal length for the central wavelength of the laser λo. Within the paraxial approximation, the focal irradiance distribution of a long pulse focused by a refractive lens (RL) or a DL of the same numerical aperture (NA) and focal length is expected to show similar behavior [2]. However, for sub 100 fs pulses, important differences appear owing to the large spectral bandwidth of ultrashort pulsed radiation [3]. Recently, measurements of the intensity ablation threshold by defocusing a RL have been carried out for 100 fs pulses [4]. In this contribution, we compare the ablation region obtained under defocusing conditions for both RL and DL with sub 100 fs pulses.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.