Pixelated phase computer holograms for the accurate encoding of scalar complex fields

Abstract

We discuss a class of phase computer-generated holograms for the encoding of arbitrary scalar complex fields. We describe two holograms of this class that allow high quality reconstruction of the encoded field, even if they are implemented with a low-resolution pixelated phase modulator. In addition, we show that one of these holograms can be appropriately implemented with a phase modulator limited by a reduced phase depth.

Higher-dimensional orbital-angular-momentum-based quantum key distribution with mutually unbiased bases

“…A beam-splitter was used to separate the collinear signal and idler photons (depicted by arms A and B) which were directed and imaged (2×) from the plane of the crystal onto spatial light modulators (SLMs) by a 4-f telescope. The SLMs were used to execute the filter measurements and were encoded to manipulate both the phase and amplitude of the incident light [27][28][29][30], allowing only one particular superposition of the LG modes to be detected by the detector, while all the others are blocked. False colour images of the types of filters (or holograms) encoded on the SLMs are presented in Fig.…”

Laguerre-Gaussian mode division multiplexing in multimode fiber using SLMs in VCSEL arrays

“…The LG mode generation from the SLM is adapted from [52], with the number of lenses reduced to one and the Fourier transform of the desired mode directly displayed on the SLM, encoded in binary phase, so as to obtain the complex field of the desired mode on the Fourier plane by isolating the first diffraction order. The channel degradation is due to mode coupling within the MMF channel.…”

“…The five SLMs are connected to a computer to program the appropriate holograms for generating 25 modes. The LG mode generation from the SLM is adapted from [52], the difference being that the number of lens is reduced to one, thus the Fourier transform of the modal field is displayed directly on the SLM, encoded in binary phase, so as to obtain the complex field of the desired mode as the first diffraction order on the Fourier plane. Let the x-polarized transverse modal field of the c-th LG mode to be derived from the k-th SLM, E k SLM r; ϕ ð Þ be expressed as [55]:…”

“…This yields the complex field: ð Þis binarized according to the third type of CGH in [52] and displayed on the SLM, expressed as a Fourier series: …”

Novel Optimization Method of Phase-Only Computer-Generated Hologram Using the Phase-Shift Characteristic

“…위상변조만을 이용하는 방법은 이상적인 CGH를 계산하고 이를 최적화하는 과정이 필요하다. 하지만, 푸리에 급수와 Jacobi-Anger identity를 이용한 기존의 계산방법은 수치해석 적으로 최적의 값을 찾아내야 하기 때문에 계산속도 측면에 서 단점이 존재하였다 [14] . …”