Modifications of holographic diffractive doublets for collimation of highly elliptical beams from edge-emitting diode-lasers

摘要

Holographic diffractive doublets axe optional systems for collimation of highly elliptical light beams, which are emitted from edge of diode-lasers. The first element converts an impinging astigmatic divergent beam into a cylindrical divergent beam, and the second element transforms the cylindrical beam into a collimated beam. In contrast to previous concept of the doublet with perpendicular input and output, another non-parallel scheme is considered, with the cylindrical wave front from the first element perpendicularly impinging upon the second element. A strongly off-axis holographic set-up is used for recording of diffractive elements in photoresist layers deposited on glass substrates.