Compensation of beam ellipticity and astigmatism based on holographic diffractive elements recorded onto spherical substrates

Autor: Vaclav Malina, Ivo Aubrecht, Jan Pala, Miroslav Miler
Rok vydání: 2004
Předmět:
Zdroj: Journal of Modern Optics. 51:2257-2266
ISSN: 1362-3044
0950-0340
DOI: 10.1080/09500340408232528
Popis: Edge emitting diode lasers with their divergent, highly elliptical and astigmatic beams in the visible spectrum are widely used in all branches of photonics. Usually the beams must be transformed into circular anastigmatic beams for the majority of applications. Holographic diffractive elements on spherical substrates are devised for transformation of beams to circular collimated beams. An off-axis holographic set-up is used to record diffractive elements into a thin photoresist layer as shallow surface-relief gratings working in reflection mode with curved and chirped grooves. The elements are destined for the diode lasers emitting at a suitable wavelength and with appropriate ellipticity and astigmatism. The performance of the elements is tested on the basis of intensity patterns and the elements produced at a focal plane on their illumination with a collimated expanded beam of a HeNe laser.
Databáze: OpenAIRE