Spectral control of the orbital angular momentum of a laser beam based on 3D properties of spiral phase plates fabricated for an infrared wavelength

Abstract

This paper examines the spectral properties of a spiral phase plate (SPP) generating orbital angular momentum (OAM) beams. A simple method is proposed for calculating the resulting OAM by measuring only two maximum expansion coefficients. A comparative numerical simulation of the proposed and traditional methods is performed. An SPP is fabricated for generation of an OAM with integer values at infrared and visible wavelengths. Qualitative experimental studies of the changes in a generated OAM with a change in the operating wavelength are performed using the spatial filtering method. The experimental results are found to agree with the results of numerical simulation. Beams with integer and fractional OAM values are obtained experimentally by changing the wavelength.

Recent Advances in Generation and Detection of Orbital Angular Momentum Optical Beams—A Review

“…Note, the classical diffraction SPPs are manufactured for a specific laser wavelength. However, refractive (with high relief) SPPs have been successfully used for different wavelengths [ 110 , 111 ] allowing the OVs generation of various orders, including fractional orders [ 58 ]. The advantages of SPPs made from solid materials are high damage threshold and efficiency.…”

“… Methods to generate light with OAM: ( a ) Shift in the OAM order by illuminating a 3D element with the laser light of different wavelengths [ 58 ]; ( b ) OAM generator via CGH [ 59 ]; ( c ) Schematic of the OV beam generator from MS [ 60 ]; and ( d ) The schematic illustration of the OV beam generator on the embedded multi-WG [ 61 ]. …”

“…Figure 2 demonstrates four different methods used for the creation of light with OAM which are widely used among the researchers [ 58 , 59 , 60 , 61 ]. Another device, comprising a mutable amplitude splitter (VAS) and an OAM emitter, has recently been suggested, in which the comparative amplitude of the two OAM states with inverse chirality can be tuned [ 62 ].…”

Spatial-Light-Modulator-Based Multichannel Data Transmission by Vortex Beams of Various Orders

“…Algorithms are also known that allow one to calculate the field OAM by three [ 49 ] and even two [ 50 ] expansion coefficients. However, in all cases, it is necessary to accurately measure the relative values of these coefficients.…”

Vortex Laser Based on a Plasmonic Ring Cavity

“…In order to obtain OAM light, one can modulate the wave front of a coherent light. The wave-front modulations are mostly based on changing the optical path difference, employing a geometry phase, or controlling diffraction on demand with suitable optical elements, such as spiral phase plates, lens, Pancharatnam-Berry phase elements, and holograph [16][17][18][19][20][21][22][23] and so forth. In addition, the direct generation of OAM light within the laser cavity has been developed, to the great attention of researchers [24][25][26][27][28][29][30][31][32][33][34].…”