Dataset on diffraction efficiency and polarization ratio of the +1 order beam diffracted by a binary hologram displayed on ferroelectric and twisted nematic Liquid Crystal Spatial Light Modulators

Description

This dataset describes the diffraction efficiency, polarization angle and polarization ratio of the +1 order diffracted beam for ferroelectric and twisted nematic Liquid Crystal based Spatial Light Modulators (LCSLM) and for different orientations of the incident beam polarization. We consider SXGA-R3 Ferroelectric type LCSLM, and LC-R 720, and LC-R 1080 twisted nematic type LCSLM. The dataset also includes reflection efficiency, polarization angle and polarization ratio of the reflected beam for LC-R 720, and LC-R 1080 and for different orientations of the incident beam polarization. The measured data show that as the polarization of the incident beam is varied the diffraction efficiency in case of SXGA-R3 remains same although the polarization of the diffracted beam changes while in case of LC-R 720, and LC-R 1080 the behavior is opposite. The dataset (LCSLM-DiffractionEfficiency.zip) contains three csv files namely, SXGA-R3-DE.csv containing the data using the ferroelectric LCSLM (SXGA-R3), LC-R720-DE.csv containing the data using the twisted nematic LCSLM (LC-R 720) and LC-R1080-DE.csv containing the data using the nematic LCSLM (LC-R 1080). In each csv file column 1 displays the incident beam power, column 2 displays the polarization angle of the incident beam, column 3 displays the power in the +1 order beam without analyzer normalized by the incident power (i.e. diffraction efficiency), column 4 displays the dominant polarization direction in the +1 order beam, column 5 displays the normalized power in the +1 order beam with the analyzer in the dominant polarization direction, column 6 displays the normalized power in the +1 order beam with the analyzer perpendicular to the dominant polarization direction, and column 7 displays polarization ratio of the +1 order beam (i.e. column 5/ column 6). The dataset (LCSLM-ReflectionEfficiency.zip) has eight csv files namely, LC-R720-RE_g=i.csv where i=0, 50, 150, 255 corresponding to different grayscale values of the uniform pattern for the twisted nematic LCSLM (LC-R 720) and LC-R1080-RE_g=i.csv where i=0, 50, 150, 255 corresponding to different grayscale values of the uniform pattern for the twisted nematic LCSLM (LC-R 1080). In each csv file column 1 displays the incident beam power, column 2 displays the polarization angle of the incident beam, column 3 displays the power in the reflected beam without analyzer normalized by the incident power (i.e. reflection efficiency), column 4 displays the dominant polarization direction of the reflected beam, column 5 displays the normalized power of the reflected beam with the analyzer in the dominant polarization direction, column 6 displays the normalized power of the reflected beam with the analyzer perpendicular to the dominant polarization direction, and column 7 displays polarization ratio of the reflected beam (i.e. column 5/ column 6).

Steps to reproduce

A laser beam of 632.8 nm wavelength and polarized at a given angle (as measured with respect to the vertical axis in the clockwise direction, seen against the propagation direction) is incident on the LCSLM panel. The LCSLM displays either a binary hologram (with pixel values 0 and 255) or a uniform pattern with a given grayscale value (say g). In the case of the binary hologram, the LCSLM panel diffracts the incident beam into a number of orders, primarily, +1, 0 and -1 orders. The power carried by the +1 order beam or the reflected beam, in the case of the uniform pattern, relative to the incident beam power is measured directly without an analyzer and also with an analyzer. The polarization axis of the analyzer is also measured with respect to the vertical axis in the clockwise direction, seen against the propagation direction. The polarization axis of the beam incident on the LCSLM is changed by rotating the fast axis of a half wave plate kept in the incident beam path.

Institutions

• Indian Institute of Technology Guwahati

  Assam, Guwahati

Categories

Funders

• Science and Engineering Research Board

  Department of Science and Technology

  New Delhi

  Grant ID: SR/S2/LOP-011/2010
• Ministry of Electronics and Information Technology

  New Delhi

  Grant ID: 2(4)/2011-PDD

Licence