Invariant grating pseudoimaging using polychromatic light and a finite extension source

Sanchez‐Brea, Luis Miguel; Sáez–Landete, José; Alonso, José María Rabal; Bernabéu, Eusebio

doi:10.1364/ao.47.001470

Cited by 9 publications

(8 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When a collimated beam passes through a diffraction grating, self-images of the grating appear in the near field at certain distances, known as Talbot distances, which are z T ¼ np 2 =λ, where p is the period of the grating, λ is the wavelength, and n is an integer. On the other hand, when the light beam is not collimated, the Talbot distances change [17][18][19]. In both cases moiré fringes can be obtained when a second grating with the same period as the first is placed at some Talbot plane.…”

Section: Introductionmentioning

confidence: 99%

Collimation method using a double grating system

et al. 2010

Self Cite

View full text Add to dashboard Cite

We present a collimation technique based on a double grating system to locate with high accuracy an emitter in the focal plane of a lens. Talbot self-images are projected onto the second grating producing moiré interferences. By means of two photodetectors positioned just behind the second grating, it is possible to determine the optimal position of the light source for collimation by measuring the phase shift between the signals over the two photodetectors. We obtain mathematical expressions of the signal in terms of defocus. This allows us to perform an automated technique for collimation. In addition, a simple and accurate visual criterion for collimating a light source using a lens is proposed. Experimental results that corroborate the proposed technique are also presented.

show abstract

Section: Introductionmentioning

confidence: 99%

Collimation method using a double grating system

et al. 2010

Self Cite

View full text Add to dashboard Cite

show abstract

“…This condition restricts freedom in designing the application systems. There are some papers that aim at relaxing this restriction [26][27][28]. However, the proposed grating systems do not seem to have enough contrast.…”

Section: Introductionmentioning

confidence: 99%

Relaxation of the Talbot condition in generalized grating imaging

Iwata¹,

Satoh

Moriwaki

2012

Appl. Opt.

View full text Add to dashboard Cite

We can form a grating image with two gratings having different pitches with an extended light source. It is called generalized grating imaging or the Talbot-Lau effect. When we want to obtain high contrast image with pure absorption gratings or pure phase gratings, the separation between the two gratings is restricted. This corresponds to the Talbot condition. In this paper, we propose to use a combination of absorption grating and phase grating to relax the separation restriction. The theory of generalized grating imaging is applied to the system with this kind of grating. Simulations are performed for calculating contrast variation and show that the proposed system practically relaxes the Talbot condition. An experiment verifies the result of the simulation.

show abstract

“…Some works about cancellation or pseudocancellation of the Talbot effect with polychromatic light [8] and in double-grating systems [9] have been published. When the Talbot effect is canceled, then the intensity distribution is nearly independent of the distance from the grating to the observation plane.…”

Section: Introductionmentioning

confidence: 99%

Continuous self-imaging regime with a double-grating mask

2009

Self Cite

View full text Add to dashboard Cite

We analyze the Talbot effect produced by a mask composed of two diffraction gratings. Combinations with phase and amplitude gratings have been studied in the near-field regime. For a two-phase-gratings configuration, the Talbot effect is canceled, even when using monochromatic light; that is, the intensity distribution is nearly independent of the distance from the mask to the observation plane. Therefore, the mechanical tolerances of devices that use the Talbot effect may be improved. In addition, the spatial frequency of the fringes is quadrupled, which improves the accuracy of devices that employ this mask. An experimental verification for the best case two phase gratings, has also been performed, validating the theoretical results.

show abstract

Invariant grating pseudoimaging using polychromatic light and a finite extension source

Cited by 9 publications

References 18 publications

Collimation method using a double grating system

Collimation method using a double grating system

Relaxation of the Talbot condition in generalized grating imaging

Continuous self-imaging regime with a double-grating mask

Contact Info

Product

Resources

About