Polarization multiplexing

Figure 16.24 shows the polarization-multiplexed recorded data X, Y, and Z at the respective recording polarization angles 0 , 60 , and 120 . Each pattern was recorded with the same exposure time. The lateral distance between bits in the plane was 3 /xm. The expected refractive-index change was estimated as about 0.01. 

FIC. 16.24 Readout results of the polarization-multiplexed recorded data at the respective recording polarization angles 0°, 60°, and 120°. 

Fig. 35. The reconstruction images in polarization multiplexing holographic storage in fulgide film reconstruction image (a) of parallel circular polarization hologram (b) of orthogonal circular polarization hologram (c) of both holograms...

Application of polarization multiplexing technique in holographic interferometer... 

Plenary 10. Hiro-o Hamaguchi, e-mail address lilrama ,chem.s.u-tokvo.ac.ip (time and polarization resolved multiplex 2D-CARS). Two-dimensional (tune and frequency) CARS using broadband dye source and streak camera timing. Studies dynamic behaviour of excited (pumped) electronic states. Follows energy flow within excited molecules. Polarization control of phase of signal (NR background suppression). 

Toleutaev B N, Tahara T and Hamaguchi H 1994 Broadband (1000 cm multiplex CARS spectroscopy application to polarization sensitive and time-resolved measurements Appl. Phys. 59 369-75... 

Comparison between heat-mode and photon-mode processes is given in Table I. The main differences are the superior resolution and the possibility of multiplex recording in photon-mode systems. Because of the diffusion of heat, the resolution of heat-mode recording is inferior to that of photon-mode systems. Furthermore, photons are rich in information such as energy, polarization and coherency, which can not be rivalled by heat-mode recording. 

Fig. 6.8. A Principle of frequency-multiplexed CARS microspectroscopy A narrow-bandwidth pump pulse determines the inherent spectral resolution, while a broad-bandwidth Stokes pulse allows simultaneous detection over a wide range of Raman shifts. The multiplex CARS spectra shown originate from a 70 mM solution of cholesterol in CCI4 (solid line) and the nonresonant background of coverglass (dashed line) at a Raman shift centered at 2900 cm-1. B Energy level diagram for a multiplex CARS process. C Schematic of the multiplex CARS microscope (P polarizer HWP/QWP half/quarter-wave plate BC dichroic beam combiner Obj objective lens F filter A analyzer FM flip mirror L lens D detector S sample). D Measured normalized CARS spectrum of the cholesterol solution. E Maximum entropy method (MEM) phase spectrum (solid line) retrieved from (D) and the error background phase (dashed line) determined by a polynomial fit to those spectral regions without vibrational resonances. F Retrieved Raman response (solid line) calculated from the spectra shown in (E), directly reproducing the independently measured spontaneous Raman response (dashed line) of the same cholesterol sample...

Fig. 6.9. A Spontaneous Raman spectrum of d62-DPPC lipids and its decomposition into Lorentzian line profiles. B Normalized multiplex CARS spectra (dots) of a planar-supported bilayer and monolayer formed by d62-DPPC on a glass-water interface for parallel-polarized input beams, together with the fit using the center frequency and line width parameters extracted from the decomposition analysis in (A) (solid line). The spectrum exposure time was 0.64 s. Error bars indicate the shot-noise standard deviation (Copyright American Chemical Society [70])...

Measurement accuracy. Our r.m.s. shot to shot fluctuations are 5%, thanks to the use of reference. This accuracy does not depend on the mode of operation (spatial resolution and choice of field polarizations). It is not as good, however, in multiplex CARS, or in dilute samples, or in the vicinity of narrow lines, because other sources of noise such as photoelectron statistics and laser frequency instabilities (however small) then play a major role. 

One of the major advantages of the dispersive instrument is the possibility of computer adjusting the electronics at any spectral point such that the signal can be processed under optimum conditions. This is possible because the signal varies slowly with time, and because the data are not multiplexed. Furthermore, synchronization of the PEM retardation with the wavelength transmitted by the monochromator can be achieved, which results in maximum circular polarization at each wavelength, and therefore, an automatically calibrated signal at optimum amplitude. 

A small TN LC display can be multiplexed without the use of additional elements, because a nonlinear relationship exists between contrast and voltage, as shown in Fig. la. An addressing scheme such as shown in Fig. 2 can then be employed. Information is written into the display one row at a time. The row to be addressed is pulsed to +2 F, where Fis a suitable voltage, while all other, nonactive rows, are set to zero. Elements along a given row are addressed concurrently, by setting the columns at —1 For +1Fdepending whether a pixel is to display information or not, respectively. After the row is written, row potential is returned to zero and the next line is addressed. Polarity is reversed between frames to minimize deterioration of the LC by electrolytic processes. 

Nafie LA (2000) Dual polarization modulation a real-time, spectral-multiplex separation of circular dichroism from linear birefringence spectral intensities. Appl Spectrosc 54 1634-1645... 

The requirement of a very high and constant resistivity over time of nematic mixtures for TN-LCDs with active matrix addressing meant that new liquid crystals which met this and the other specifications, such as low viscosity and high positive dielectric anisotropy, were needed. The nitriles used in nematic mixtures for TN-LCDs with direct or multiplex addressing were soon found to be unsuitable for TN-LCDs with active matrix addressing. The polar nature of the cyano group leads to the solvation of ions from some of the layers on the... 

---