Accurate encoding of arbitrary complex fields with amplitude-only liquid crystal spatial light modulators.

We show that computer generated holograms, implemented with amplitude-only liquid crystal spatial light modulators, allow the synthesis of fully complex fields with high accuracy. Our main discussion considers modified amplitude holograms whose transmittance is obtained by adding an appropriate bias function to the real cosine computer hologram of the encoded signal. We first propose a bias function, given by a soft envelope of the signal modulus, which is appropriate for perfect amplitude modulators. We also consider a second bias term, given by a constant function, which results appropriate for modulators whose amplitude transmittance is coupled with a linear phase modulation. The influence of the finite pixel size of the spatial light modulator is compensated by digital pre-filtering of the encoded complex signal. The performance of the discussed amplitude CGHs is illustrated by means of numerical simulations and the experimental synthesis of high order Bessel beams.

[1]  F T Yu,et al.  Application of position encoding to a complex joint transform correlator. , 1995, Applied optics.

[2]  Leonard J. Porcello,et al.  Optical data processing and filtering systems , 1960, IRE Trans. Inf. Theory.

[3]  J. Burch.  A computer algorithm for the synthesis of spatial frequency filters , 1967 .

[4]  J Turunen,et al.  Realization of general nondiffracting beams with computer-generated holograms. , 1989, Journal of the Optical Society of America. A, Optics and image science.

[5]  R. Cohn,et al.  Phase calibration of spatially nonuniform spatial light modulators. , 2004, Applied optics.

[6]  A. Carnicer,et al.  Implementation of real filters in a joint transform correlator using a positive-only display , 1994 .

[7]  J Campos,et al.  Gray-level computer-generated hologram filters for multiple-object correlation. , 2000, Applied optics.

[8]  Sabino Chávez-Cerda,et al.  Parabolic nondiffracting optical wave fields. , 2004, Optics letters.

[9]  M Liang,et al.  Approximating fully complex spatial modulation with pseudorandom phase-only modulation. , 1994, Applied optics.

[10]  Francis T. S. Yu,et al.  Self-organizing optical neural network for unsupervised learning , 1990 .

[11]  Victor Arrizón.  Improved double-phase computer-generated holograms implemented with phase-modulation devices. , 2002, Optics letters.

[12]  S. Chu,et al.  Observation of a single-beam gradient force optical trap for dielectric particles. , 1986, Optics letters.

[13]  A. Stein,et al.  Controllable pulse compression in a multiple-pass-cell Raman laser. , 1980, Optics letters.

[14]  Jeffrey A. Davis,et al.  Encoding amplitude information onto phase-only filters. , 1999, Applied optics.

[15]  Bahaa E. A. Saleh,et al.  Theory and design of the liquid crystal TV as an optical spatial phase modulator , 1990 .

[16]  A. Lohmann,et al.  Complex spatial filtering with binary masks. , 1966, Applied optics.

[17]  Jari Turunen,et al.  Zeroth-order coding of complex amplitude in two dimensions , 1997 .

[18]  Juan Campos,et al.  Phase and amplitude modulation of elliptic polarization states by nonabsorbing anisotropic elements: application to liquid-crystal devices. , 2002, Journal of the Optical Society of America. A, Optics, image science, and vision.

[19]  Stanley E. Monroe,et al.  Full-face full-complex characterization of a reflective SLM , 2000, SPIE Defense + Commercial Sensing.

[20]  Sabino Chávez-Cerda,et al.  Exact nonparaxial beams of the scalar Helmholtz equation. , 2004, Optics letters.

[21]  D Mendlovic,et al.  Encoding technique for design of zero-order (on-axis) Fraunhofer computer-generated holograms. , 1997, Applied optics.

[22]  Victor Arrizón,et al.  Optimum on-axis computer-generated hologram encoded into low-resolution phase-modulation devices. , 2003, Optics letters.

[23]  C Chatwin,et al.  Two-pixel computer-generated hologram with a zero-twist nematic liquid-crystal spatial light modulator. , 2000, Optics letters.