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Journal of the Optical Society of America A

Journal of the Optical Society of America A

| OPTICS, IMAGE SCIENCE, AND VISION

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Optics InfoBase > JOSA A > Early Posting

Early Posting

Accepted papers to appear in an upcoming issue

OSA now posts prepublication articles as soon as they are accepted and cleared for production. See the FAQ for additional information.

<< Previous Page Articles 21 to 27 of 27

September


(LITH2014) Illumination source optimization in optical lithography via derivative-free optimization

  • Wen Lv, Shiyuan Liu, Xiaofei Wu, and Edmund Lam
  • received 07/07/2014; accepted 09/29/2014; posted 10/03/2014; Doc. ID 216384
  • [full text: PDF (978) KB)]
  • Abstract: Illumination source optimization (SO) in optical lithography is generally performed under a simulated model which does not consider some critical effects, such as vectorial nature of light and mask topography. When the numerical aperture becomes large and the critical dimension reaches the sub-wavelength nodes, the prediction of this model generally fails, and therefore the previous works based on this model become inaccurate. In order to compute SO correctly, we first propose a new source pattern representation method which has moderate parameter variations but remains complete in solution space. Then, we develop a derivative-free optimization (DFO) method to optimize these parameters under a rigorous simulated model. Unlike gradient-based techniques, DFO methods do not require a closed-form formulation of the model and is independent of the form of the cost function.

Keywords (OCIS):

  • (110.5220) Imaging systems : Photolithography
  • (110.1758) Imaging systems : Computational imaging
  • (110.4235) Imaging systems : Nanolithography

(LITH2014) Efficient representation of mask transmittance functions for vectorial lithography simulations

  • Xinjiang Zhou, Chaunwei Zhang, Hao Jiang, Haiqing Wei, and Shiyuan Liu
  • received 07/09/2014; accepted 09/29/2014; posted 10/03/2014; Doc. ID 216619
  • [full text: PDF (830) KB)]
  • Abstract: In this paper, a generalized method to efficiently represent the incident-angle-dependent mask transmittance function (MTF) of a thick mask is proposed. This method expands the MTF into a series expansion, which consists of a set of predetermined basis functions weighted by a set of predetermined expansion coefficients. The predetermined basis functions are independent of the incident angles and thus may be computed offline and stored, while the expansion coefficients depend only on the incident angles and can be rapidly calculated online. Near field and optical image simulations of thick masks have demonstrated the excellent accuracy and superior speed performance.

Keywords (OCIS):

  • (050.1960) Diffraction and gratings : Diffraction theory
  • (110.5220) Imaging systems : Photolithography
  • (110.1758) Imaging systems : Computational imaging

A theoretical performance model for single image depth from defocus

  • Pauline Trouvé-Peloux, Frederic Champagnat, Guy Le Besnerais, and Jerôme Idier
  • received 07/25/2014; accepted 09/23/2014; posted 10/08/2014; Doc. ID 217597
  • [full text: PDF (718) KB)]
  • Abstract: In this paper we present a performance model for depth estimation using Single Image Depth From Defocus (SIDFD). Our model is based on an original expression of the Cramér Rao Bound (CRB) in this context. We show that this model is consistent with the expected behavior of SIDFD. We then study the influence on the performance of the optical parameters of a conventional camera such as the focal length, the aperture and the position of the in-focus plane. We derive an approximate analytical expression of the CRB away from the in-focus plane and we propose an interpretation of the SIDFD performance in this domain. Finally, we illustrate the predictive capacity of our performance model on experimental data comparing several settings of a consumer camera.

Keywords (OCIS):

  • (100.3190) Image processing : Inverse problems
  • (150.5670) Machine vision : Range finding
  • (110.1758) Imaging systems : Computational imaging

Blurred and Noisy Images Pairs in Parallel Optics

  • Iftach Klapp, Nir Sochen, and David Mendlovic
  • received 03/20/2014; accepted 09/22/2014; posted 09/23/2014; Doc. ID 208276
  • [full text: PDF (574) KB)]
  • Abstract: In previous works we have shown that Parallel Optics (PO) architecture can be used to improve the system matrix condition, which results in improving its immunity to additive noise in the image restoration process. Parallel Optics is composed of a “main” system and an “auxiliary” system. Previously, we suggested the “trajectories” method to realize the Parallel Optics. In that method, a required “auxiliary” system is composed from “auxiliary” optics with a pixel confined response, followed by signal processing. In this paper, we emphasize the important secondary effects of the “trajectories” method. We show that in such a system, where the post processing comes after the detection, the post-processing acts as a noise filter, hence allowing to work with noisy data in the “auxiliary” channel. Roughly speaking, the SNR of an imaging system depends on the Numerical Aperture (NA). It follows that the “main” system, which typically has higher NA, also has higher SNR. Hence in the PO system, the ratio between the NA values of the “main” and “auxiliary” systems is expected to dictate the gap between their SNR values. In this paper, we show that when the system is implemented by the “trajectories” method, this expectation is too conservative. It is shown that due to the noise filtering, the “auxiliary” system can be noisier than expected. This claim is proved analytically, and verified and exemplified by using experimental measurements.

Keywords (OCIS):

  • (070.6110) Fourier optics and signal processing : Spatial filtering
  • (080.1010) Geometric optics : Aberrations (global)
  • (100.3190) Image processing : Inverse problems
  • (170.3010) Medical optics and biotechnology : Image reconstruction techniques

The Atomic Lighthouse Effect

  • C. Máximo, R. Kaiser, Ph. Courteille, and R. Bachelard
  • received 07/29/2014; accepted 09/22/2014; posted 09/23/2014; Doc. ID 219885
  • [full text: PDF (623) KB)]
  • Abstract: We investigate the deflection of light by a cold atomic cloud when the light-matter interaction is locally tuned via the Zeeman effect using magnetic field gradients. This ``lighthouse' effect is strongest in the single-scattering regime, where deviation of the incident field is largest. For optically dense samples, the deviation is reduced by collective effects, as the increase in linewidth leads to a decrease of the magnetic field efficiency.

Keywords (OCIS):

  • (020.0020) Atomic and molecular physics : Atomic and molecular physics
  • (020.1670) Atomic and molecular physics : Coherent optical effects
  • (020.7490) Atomic and molecular physics : Zeeman effect
  • (290.4210) Scattering : Multiple scattering

Holographic laser Doppler imaging of microvascular blood flow

  • C. Magnain, A. Castel, T. Boucneau, M. Simonutti, I. Ferezou, A. Rancillac, T. Vitalis, J. Sahel, M. Paques, and M. Atlan
  • received 09/15/2014; accepted 09/17/2014; posted 10/10/2014; Doc. ID 223162
  • [full text: PDF (1823) KB)]
  • Abstract: We report on local superficial blood flow monitoring in biological tissue from laser Doppler holographic imaging. In time-averaging recording conditions, holography acts as a narrowband bandpass filter, which, combined with a frequency-shifted reference beam, permits frequency-selective imaging in the radiofrequency range. These Doppler images are acquired with an off-axis Mach-Zehnder interferometer. Microvascular hemodynamic components mapping is performed in the cerebral cortex of the mouse and the eye fundus of the rat with near-infrared laser light without any exogenous marker. These measures are performed from basic inverse-method analysis of local first-order optical fluctuation spectra at low radiofrequencies, from 0 Hz to 100 kHz. Local quadratic velocity is derived from Doppler broadenings induced by fluid flows, with elementary diffusing wave spectroscopy formalism in backscattering configuration. We demonstrate quadratic mean velocity assessment in the 0.1-10 mm/s range in vitro, and imaging of superficial blood perfusion with a spatial resolution of about 10 microns in rodent models of cortical and retinal blood flow.

Keywords (OCIS):

  • (040.2840) Detectors : Heterodyne
  • (170.1470) Medical optics and biotechnology : Blood or tissue constituent monitoring
  • (170.3340) Medical optics and biotechnology : Laser Doppler velocimetry
  • (090.1995) Holography : Digital holography

February


(CV) Independence and interaction of luminance and chromatic contributions to spatial hyperacuity performance

  • Bonnie Cooper and Barry Lee
  • received 09/30/2013; accepted 02/02/2014; posted 02/03/2014; Doc. ID 198653
  • [full text: PDF (1336) KB)]
  • Abstract: Here we test interactions of luminance and chromatic input to spatial hyperacuity mechanisms. First, we tested alignment with matching or mismatching (contrast polarity or modality) grating pairs that were adjusted to detection threshold. Thresholds with mismatched pairs were significantly elevated. Second, we determined alignment acuity as a function of luminance or chromatic contrast alone or in the presence of contrast pedestals. For in-phase pedestal conditions, performance followed the envelope of the more sensitive mechanism. However, polarity reversals revealed an asymmetric effect for luminance and chromatic conditions. This suggests that luminance can overrule chromatic mechanisms in hyperacuity; we interpret these findings in the context of spatial mechanisms.

Keywords (OCIS):

  • (330.1720) Vision, color, and visual optics : Color vision
  • (330.5510) Vision, color, and visual optics : Psychophysics
  • (330.6100) Vision, color, and visual optics : Spatial discrimination

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