Title :
25-channel nematic liquid-crystal optical time-delay unit characterization
Author_Institution :
Dept. of Electr. & Comput. Eng., Central Florida Univ., Orlando, FL, USA
Abstract :
A 25-channel, 1-bit, free-space, nematic liquid crystal (NLCU) spatial light modulator (SLM)-based optical time delay unit (OTDU) is demonstrated with worst case electrical signal-to-noise ratios (SNR´s) ranging from 50-60 dB for various delay/no-delay modes of operation and with a worst case -42,3-dB electrical channel isolation/crosstalk level. For comparison, single channel performance neglecting crosstalk noise but including within-channel leakage noise gives electrical SNR´s from 74-85 dB, indicating that the leakage signal in this OTDU is minimal compared to crosstalk, To lower crosstalk, path-difference compensated imaging optics must be used by the OTDU.<>
Keywords :
antenna accessories; antenna phased arrays; delays; liquid crystal devices; nematic liquid crystals; optical crosstalk; optical noise; spatial light modulators; 25-channel nematic liquid-crystal optical time-delay unit characterization; crosstalk level; crosstalk noise; delay/no-delay modes; electrical channel isolation; leakage signal; path-difference compensated imaging optics; single channel performance; spatial light modulator; within-channel leakage noise; worst case electrical signal-to-noise ratios; Delay effects; Optical arrays; Optical crosstalk; Optical devices; Optical interconnections; Optical mixing; Optical modulation; Optical noise; Phased arrays; Signal to noise ratio;
Journal_Title :
Photonics Technology Letters, IEEE
