Source-linked AI summary
Encoding complex fields by using a phase-only optical element: mitigation of pixel crosstalk effects
Miguel Carbonell-Leal, Omel Mendoza-Yero
TL;DR
The paper examines how pixel crosstalk undermines phase-only encoding of complex fields with PA-LCoS SLMs. It models non-uniform pixel-cell responses, proposes generalized sampling, and experimentally evaluates retrieved amplitude and phase images using single-camera phase shifting.
Problem
Pixel crosstalk alters phase responses at abrupt encoded-phase discontinuities, limiting the experimental realization and image quality of phase-only complex-field encoding with PA-LCoS SLMs.
Method
The paper models each pixel cell with non-uniform central and border zones, uses generalized sampling with larger pixel cells, and measures retrieved complex fields through a single-camera phase-shifting implementation.
Results
About 70% of a single pixel cell can generate unexpected phase modulation under Nyquist-limit conditions, while larger sampling cells make measured irradiance approach theory and improve retrieved image quality.
Takeaways & Limitations
Pixel-cell size presents a trade-off: increasing it mitigates crosstalk and improves contrast and sharpness, but excessive enlargement causes resolution loss.
Abstract
from arXiv · showhide
In this letter we report on the effects of pixel crosstalk on the experimental realization of a reported encoding method (Opt. Lett. 39, 1740 (2014)) with PA-LCoS SLMs. We found that, under Nyquist limit condition, about 70% of a single pixel cell can generate unexpected phase modulation. In order to approach uniform phase modulation, and consequently improve the quality of measured amplitude and phase images, a generalized sampling scheme is proposed. To corroborate our proposal, proper experiments were carried out. On this point, a particular implementation of the well-established phase shifting technique allows us to measure the retrieved complex field by using just a single camera.
Complete references
The references include prior work on SLM-based complex-field encoding and phase-response calibration, including studies of internal reflections and related device effects.
- References 1–3 cover earlier approaches to encoding arbitrary or full-complex optical fields with liquid-crystal spatial light modulators.
- Reference 22 studies time fluctuations of phase modulation in a liquid-crystal-on-silicon display and their effects in diffractive optics.