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Title: Comment on 'Tunable three-dimensional intensity distribution by a pure phase-shifting apodizer'

Abstract

In the past few years, many radially symmetric pupil masks have been designed for the control of the light intensity distribution near the geometrical focus of optical systems. A recent paper by Gao et al. [Appl. Opt. 44, 4870 (2005)] analyzed the performance of binary 0-{pi}phase-only masks for an incident beam with Gaussian amplitude. Some inaccuracies of the analysis concerning the evolution of the Strehl ratio with the mask parameters are corrected.

Authors:
; ;
Publication Date:
OSTI Identifier:
20854006
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Optics; Journal Volume: 46; Journal Issue: 2; Other Information: DOI: 10.1364/AO.46.000180; (c) 2007 Optical Society of America; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AMPLITUDES; COOLING; FOCUSING; LASERS; LENSES; OPTICAL SYSTEMS; PERFORMANCE; PHASE SHIFT; VISIBLE RADIATION

Citation Formats

Canales, Vidal F., Oti, Jose E., and Cagigal, Manuel P. Comment on 'Tunable three-dimensional intensity distribution by a pure phase-shifting apodizer'. United States: N. p., 2007. Web. doi:10.1364/AO.46.000180.
Canales, Vidal F., Oti, Jose E., & Cagigal, Manuel P. Comment on 'Tunable three-dimensional intensity distribution by a pure phase-shifting apodizer'. United States. doi:10.1364/AO.46.000180.
Canales, Vidal F., Oti, Jose E., and Cagigal, Manuel P. Wed . "Comment on 'Tunable three-dimensional intensity distribution by a pure phase-shifting apodizer'". United States. doi:10.1364/AO.46.000180.
@article{osti_20854006,
title = {Comment on 'Tunable three-dimensional intensity distribution by a pure phase-shifting apodizer'},
author = {Canales, Vidal F. and Oti, Jose E. and Cagigal, Manuel P},
abstractNote = {In the past few years, many radially symmetric pupil masks have been designed for the control of the light intensity distribution near the geometrical focus of optical systems. A recent paper by Gao et al. [Appl. Opt. 44, 4870 (2005)] analyzed the performance of binary 0-{pi}phase-only masks for an incident beam with Gaussian amplitude. Some inaccuracies of the analysis concerning the evolution of the Strehl ratio with the mask parameters are corrected.},
doi = {10.1364/AO.46.000180},
journal = {Applied Optics},
number = 2,
volume = 46,
place = {United States},
year = {Wed Jan 10 00:00:00 EST 2007},
month = {Wed Jan 10 00:00:00 EST 2007}
}
  • I thank Canales et al. very much for their attention to the effect of the phase apodizer, especially for their comment on my paper [Appl. Opt. 44, 4870(2005)]. I reinvestigated the three-dimensional intensity distribution by a pure phase-shifting apodizer, and the main results on focal shift, focal split, and three intensity distributions are correct.However, the changing principle of the Strehl ratio is wrong, as Canales et al. show in their comment. Here, I show the cause leading to the erroneous result and give the correct dependence of the Strehl ratio on the inner radius and relative waist width. I ammore » very sorry for the incorrect results in the paper.« less
  • Three-dimensional shape measurements by sinusoidal fringe projection using phase-shifting interferometry algorithms are distorted by the nonlinear response in intensity of commercial video projectors and digital cameras. To solve the problem, we present a method that consists in projecting and acquiring a temporal sequence of strictly binary patterns, whose (adequately weighted) average leads to a sinusoidal fringe pattern with the required number of bits. Since binary patterns consist of ''ones'' and ''zeros'' - and no half-tones are involved - the nonlinear response of the projector and the camera will not play a role, and a nearly unit contrast gray-level sinusoidal fringemore » pattern is obtained. Validation experiments are presented.« less
  • Purpose: To compare dose distribution and normal tissue sparing in partial-breast treatment using three-dimensional conformal radiotherapy (3D-CRT) vs. intensity-modulated radiotherapy (IMRT). Methods and Materials: Sixty-three patients with Tis-1N0M0 breast cancer were treated on a Phase II prospective accelerated partial-breast IMRT protocol at two facilities between April 2004 and January 2006. Fifty-six patients had data sets sufficient to adequately contour all structures. These cases were subsequently replanned with 3D-CRT techniques using the same contours, to compare the dose distribution patterns of 3D-CRT vs. IMRT. Results: The average planning target volume (PTV) to ipsilateral breast (IB) ratio was 24% (range, 7-58%). Themore » average volume of IB receiving 25%, 50%, 75%, and 100% of the prescribed dose was 4.0%, 5.0%, 5.5%, and 10.5% less with IMRT than with 3D (p < 0.01). The dose reduction to normal breast was further improved in the subset of patients whose PTV to IB ratio was >25%, and in patients with contoured breast volume <750 cm{sup 3}. No difference was detected in delivery to the lumpectomy cavity or clinical target volume. The PTV volume receiving 95% of the dose was higher in the 3D conformal plans (p < 0.01), but no significant difference was observed in the PTV volume receiving 90% (p = 0.17). The irradiated heart and lung volumes were small with both techniques but also favored IMRT. Conclusions: In T1N0 patients treated with external beam partial-breast radiotherapy, IMRT improves normal tissue sparing in the ipsilateral breast compared with 3DRT, without compromising dose delivery to the lumpectomy cavity and clinical target volume.« less
  • A new two-step phase-shifting fringe projection profilometry is proposed. The slowly variable background intensity of fringe patterns is removed by the use of an intensity differential algorithm. The high-resolution differential algorithm is achieved based on global interpolation of fringe gray level on a subpixel scale. Compared with the traditional three- or four-step phase-shifting method, the profile measurement is sped up with this approach.Computer simulation and experimental performance are evaluated to demonstrate the validity of the proposed measurement method. The experimental results compared with those of the four-step phase-shifting method are presented.