Cross-talk considerations for angular and phase-encoded multiplexing in volume holography

Cavity-enhanced eigenmode and angular hybrid multiplexing in holographic data storage systems

“…This is likely due to the crosstalk inherent in page base holography using image bearing object beams [8], but this crosstalk could also be due to several other factors: SLM phase error, SLM coupled amplitude modulation, Gaussian beam imperfections, and stray light.…”

“…all include the effects of dephasing in broadband signal recording and show that orthogonal phase code multiplexing provides overall crosstalk to signal ratios which are a factor of two lower than those of angular multiplexing [8]. Such reduced crosstalk is appealing for reducing bit error rates and increasing recording density, but cavity eigenmode multiplexing cannot completely replace angular multiplexing for two reasons.…”

“…Cavities can also sustain orthogonal modes for reference beams according to their eigenmodes. These eigenmodes are an inherently orthogonal set of functions, which means that they can be used as orthogonal phase codes to providing another DOF in HDSS multiplexing [8][9][10], bringing it closer to the 3D limit when effectively combined with angular multiplexing…”

Holographic Data Storage Systems

“…The result is crosstalk between multiplexed holograms. To understand the impact of crosstalk, we use a reciprocal space, or -space, formalism [9], [28], [32], [34]- [36]. A signal beam comprising a data page and a reference beam generate a hologram having spectrum of grating wave vectors.…”

“…When discrete pixels are stored in a Fourier transform arrangement, so that rows of pixels span the dimension parallel to the reference wave vectors, the relative crosstalk takes on the form [32] SNR (27) in which is the number of columns of pixels. 2) Wavelength Multiplexing: Wavelength multiplexing consists of hologram formation in which each reference wave consists of a plane wave of a different wavelength incident at the same angle, such that (28) where now and the corresponding angular frequency vary but the orientation of is the same for all reference beams.…”