6533b7dafe1ef96bd126e0c5

RESEARCH PRODUCT

Axial behavior of diffractive lenses under Gaussian illumination: complex-argument spectral analysis

Pedro AndrésA. PonsManuel Martínez-corralCarlos J. Zapata-rodríguez

subject

PhysicsDiffractionFresnel zonebusiness.industryTruncationGaussianInterference (wave propagation)Atomic and Molecular Physics and OpticsElectronic Optical and Magnetic Materialssymbols.namesakeOpticsTransmittancesymbolsFresnel numberComputer Vision and Pattern RecognitionbusinessGaussian beam

description

We present a general procedure to analyze the axial-irradiance distribution generated by an unlimited diffractive lens under coherent, Gaussian illumination. The resulting on-axis diffraction pattern, which is evaluated in terms of the power complex spectrum of the Fresnel-zone transmittance, explicitly depends on the truncation parameter that we define, which evaluates the effective number of zones illuminated by the Gaussian beam. Depending on the value of this parameter, different kinds of axial behavior are observed. In particular, for moderate values a multiple-focal-shift phenomenon appears, and a simple formula for its evaluation is presented. Additionally, for low values of the truncation parameter, a focal-merge effect is observed in multifocal zone plates.

https://doi.org/10.1364/josaa.16.002532