Phase-only liquid crystal spatial light modulator for wavefront correction with high precision

Abstract

We introduce a novel parallel-aligned liquid-crystal (LC) spatial light modulator (SLM) that has been designed to operate in a phase-only mode for wave-front correction. We measured and analyzed theoretically the electro-optic characteristics of the LC SLM and obtained a peak-to-valley value of 0.07049lambda(lambda= 0.6328microm) after correction. A Strehl ratio of 0.989 indicates the approximate upper limit of an aberrated wave front that the LC SLM can correct when it is used in an adaptive optical system.

Implementing focal-plane phase masks optimized for real telescope apertures with SLM-based digital adaptive coronagraphy

“…The functional details of liquid crystals (LC) SLM panels have been described in-depth elsewhere [27][28][29][30], and the study of their technical relevance and hardware limitations as adaptive coronagraphs for high-contrast imaging is currently still work-in-progress [26], thus not described in details herein. As a brief description, PAN-LCOS panels enable pixelated phase-only modulation of a linearly polarized incoming wavefront, by applying an electric field to each individual pixel cell to proportionally tilt the LC molecules along the z-axis, which will vary the amount of birefringence induced by the LC cell, and in turn modulate the phase for linearly polarized incoming light.…”

Electro-Optical Modulation in Planar Aligned Ferroelectric Liquid Crystals with Subwavelength Helix Pitch

“…This task is relevant both to traditional areas of optics, including adaptive optics and holographic storage devices, and also for intensively developing fields of science and technology such as holographic displays or optical manipulation of microscopic and nano-scale objects [4][5][6][7][8][9]. Pure phase modulation of light, when the phase shift can be smoothly tuned from zero to 2π in electric field E at frequency around 1 kHz or more and without any essential change of the light ellipticity, is required for development of such modern photonic devices.…”

Two-photon polymerization with optimized spatial light modulator

“…Wavefront distortion determination methods may apply wavefront sensors [29]- [31], interferometry [24] or monitor focal spot distribution [26,28]; the correction may apply Zernike polynomials [26,28,31], perform the correction in domains of the SLM [32,33] or apply a LaguerreGauss beam to optimize the wavefront [25]. The correction can even be performed for large area SLMs [34]. Some of these methods are intended to correct the aberrations of the entire optical pathway [32,33], some only that of the SLM separately [24,31,34].…”

“…The correction can even be performed for large area SLMs [34]. Some of these methods are intended to correct the aberrations of the entire optical pathway [32,33], some only that of the SLM separately [24,31,34]. What is common is that the methods use exactly the phase shifting ability of the SLM to achieve the correction: a calculated or approximated correction hologram generates the inverse phase shift of what the surface distortion created.…”