Adaptation of an existing diffractive mono-mode beam shaping design to compensate a wavelength change

Applications may vary with time, and so may the technical realization of these applications. Lasers change and consequently application wavelengths, due to requirements imposed by material changes, power constraints, scaling of lateral features, or other parameters and specifications. In applications where diffractive optical elements (DOEs) are employed a change in laser or wavelength usually demands not only a new fabrication batch but a redesign of the diffractive structure. This is almost always the case in the special application of laser beam shaping where a DOE is designed to redistribute the energy of a specific laser beam profile, generally into a flat-top intensity profile (either round or square). In this paper we will describe how a mono-mode beam shaping DOE design for 355 nm was adapted to compensate a wavelength change to 532 nm. A preliminary telescope is necessary to ensure that the input beam retains the initial properties of beam waist and beam diameter. In this case, the original DOE design can be maintained with some minor compensation in phase depth for the wavelength change and in positioning of the elements to compensate the scaled diffraction angles. Further data will be shared showing a side by side comparison of testing results of the 355 nm and 532 nm designs.