Bañas, Andrew Rafael1; Palima, Darwin1; Villangca, Mark Jayson1; Aabo, Thomas1; Glückstad, Jesper1
1 Department of Photonics Engineering, Technical University of Denmark2 Programmable Phase Optics, Department of Photonics Engineering, Technical University of Denmark
Generalized Phase Contrast (GPC) is an efficient method for generating speckle-free contiguous optical distributions useful in diverse applications such as static beam shaping, optical manipulation and recently, for excitation in two-photon optogenetics. To fully utilize typical Gaussian lasers in such applications, we analytically derive conditions for photon efficient light shaping with GPC. When combined with the conditions for optimal contrast developed in previous works, our analysis further simplifies GPCx2019;s implementation. The results of our analysis are applied to practical illumination shapes, such as a circle and different rectangles commonly used in industrial or commercial applications. We also show simple and efficient beam shaping of arbitrary shapes geared towards biophotonics research and other contemporary applications. Optimized GPC configurations consistently give ~84% efficiency and ~3x intensity gain. Assessment of the energy savings when comparing to conventional amplitude masking show that ~93% of typical energy losses are saved with optimized GPC configurations.
Optics Express, 2014, Vol 22, Issue 5, p. 5299-5311
Fourier optics and signal processing; Spatial filtering; Phase modulation; Laser beam shaping