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Opt Express ; 18(12): 13136-50, 2010 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-20588443


The spherical aberration induced by refractive-index mismatch results in the degradation on the quality of sectioning images in conventional confocal laser scanning microscope (CLSM). In this research, we have derived the theory of image formation in a Zeeman laser scanning confocal microscope (ZLSCM) and conducted experiments in order to verify the ability of reducing spherical aberration in ZLSCM. A Zeeman laser is used as the light source and produces the linearly polarized photon-pairs (LPPP) laser beam. With the features of common-path propagation of LPPP and optical heterodyne detection, ZLSCM shows the ability of reducing the specimen-induced spherical aberration and improving the axial resolution simultaneously.

Opt Express ; 15(18): 11601-7, 2007 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-19547519


We discuss a novel approach for numerical wave-front reconstruction which utilizes arbitrary phase step digital holography. Our experimental results demonstrate that only two digital holograms and a simple estimation procedure are required for twin-image suppression, and for numerical reconstruction. One advantage of this approach is its simplicity. Only one estimate equation needs be applied. In addition the optical system can be constructed from inexpensive, generally available elements. Another advantage is the effectiveness of the method. The tolerance of the estimated value is less than 1% different than the actual value. This means that the quality of the reconstructed image is superior. This novel approach should make the application of digital holography easier and more widely available.

Appl Opt ; 45(19): 4625-30, 2006 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-16799675


A new method to record an image through a thick dynamic phase distorting medium by using a photorefractive LiNbO3 crystal is demonstrated. The method uses only one beam of light, the object light. By making use of the photorefractive fanning effect, gratings are formed in the LiNbO3 crystal through the interference between the object light and its own fanning light. Because the time scale of the distorting fluctuation is much shorter than the writing time of the LiNbO3 crystal, the fluctuated light does not induce any fanning. Therefore only the static portion of the image is recorded in the crystal, and the intensity distribution of the image can then be reconstructed at any later time.

Appl Opt ; 44(29): 6155-62, 2005 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-16237928


We develop an angular-interrogation attenuated total reflection (ATR) metrology system for three different plasmonic sensors, namely, a conventional surface plasmon resonance (SPR) device, a coupled-waveguide SPR device, and a nanoparticle-enhanced SPR device. The proposed metrology system is capable of measuring the reflectivity spectra of the transverse magnetic mode and the transverse electric mode simultaneously. Through the optimal control of the fabrication process and use of sophisticated system instrumentation, the experimental results confirm that the developed ATR system is capable of measuring the resonant angle with an angular accuracy of 10(-4) deg.

Opt Lett ; 30(3): 305-7, 2005 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-15751893


We propose a new way to record images in a photorefractive LiNbO3 crystal. This method involves only a single object light without any reference light. We believe that the recording is attained by fanning holograms that result from interference between the object light and its scattered light. Although volume gratings are involved, the recorded pattern can be viewed not only with a laser light beam that is incident over a certain angular range but also with white light.

Appl Opt ; 44(8): 1416-25, 2005 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-15796240


A novel diffused photon-pair density wave (DPPDW) composed of correlated polarized photon pairs at different temporal frequencies and orthogonal linearly polarized states is proposed. A theory of DPPDWs is developed. A DPPDW selected by coherence gating and polarization gating that satisfies the diffusion equation has been verified experimentally. The sensitivity of amplitude and phase detection of the heterodyne signal has been improved by the properties of synchronized detection and common-path propagation of polarized pair photons in a multiple-scattering medium. Both reduced scattering coefficient micro2s' and absorption coefficient micro2alpha of the scattering medium in terms of the measured phase and amplitude of the heterodyne signal have been obtained. The detection sensitivity of micro2s' and micro2alpha and the properties of a DPPDW in a multiple-scattering medium are discussed and analyzed.

Aumento da Imagem/métodos , Interferometria/métodos , Refratometria/métodos , Difusão , Aumento da Imagem/instrumentação , Interpretação de Imagem Assistida por Computador , Interferometria/instrumentação , Fótons , Refratometria/instrumentação , Reprodutibilidade dos Testes , Espalhamento de Radiação , Sensibilidade e Especificidade