• 제목/요약/키워드: Phase polarization holography

검색결과 11건 처리시간 0.019초

Ag 및 MgF2/AsGeSeS 다층박막에서의 편광 홀로그래피 회절효율 특성 (The Properties of Diffraction Efficiency in Polarization Holography using the Ag and MgF2/AsGeSeS Multi-layer)

  • 나선웅;여철호;정홍배;김종빈
    • 한국전기전자재료학회논문지
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    • 제15권12호
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    • pp.1070-1074
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    • 2002
  • We have carried out two-beam interference experiments to form holographic gratings on As$_{40}$ Se$_{15}$ S$_{35}$Ge$_{10}$ single layer, Ag/As$_{40}$ Se$_{15}$ S$_{35}$Ge$_{10}$ multi-layer. In this study, holographic gratings have been formed using He-Ne laser(632.8nm) under different polarization combinations(intensity polarization holography, phase polarization holography). The diffraction efficiency was obtained by the +lst order intensity. The maximum diffraction efficiency of As$_{40}$ Se$_{15}$ S$_{35}$Ge$_{10}$ single layer, As$_{40}$ Se$_{15}$ S$_{35}$Ge$_{10}$ and MgF$_2$/As$_{40}$ Se$_{15}$ S$_{35}$Ge$_{10}$ multi-layer were 0.8%, 1.4% and 3.1% under intensity polarization holography, respectively.

Ag/As-Ge-Se-S 다층박막에서 편광상태에 따른 홀로그래피 격장 형성 특성 (Characteristics of the Polarization-Dependent Holographic grating formation on Ag/As-Ge-Se-S Multi-Layer)

  • 나선웅;이정태;여철호;이영종;정홍배
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 춘계학술대회 논문집 디스플레이 광소자 분야
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    • pp.85-88
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    • 2002
  • We have carried out two-beam interference experiments to form holographic gratings on chalcogenide $Ag/As_{40}Se_{15}S_{35}Ge_{10}$ multi-layer. In this study, holographic gratings have been formed using He-Ne laser(632.8nm) under different polarization combinations(intensity polarization holography, phase polarization holography). The diffraction efficiency was obtained by +1st order intensity and formed grating structure was investigated using atomic force microscopy.

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Analysis of Effect of Phase Error Sources of Polarization Components in Incoherent Triangular Holography

  • Kim, Soo-Gil
    • Journal of the Optical Society of Korea
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    • 제16권3호
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    • pp.256-262
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    • 2012
  • We derive the point-spread function of the reconstructed image from a point-source complex hologram, which includes phase error caused by polarization components, in the longitudinal direction of the point-spread function and analyze the effect of the error sources of polarization components having influence on image reconstruction of a point-source complex hologram in incoherent triangular holography.

기록빔의 편광상태에 따른 $AS_{40}Se_{15}S_{35}Ge_{10}$ 박막에서 홀로그래피 회절격자형성 특성 (Characteristics of Holographic Diffraction Grating Formation on $AS_{40}Se_{15}S_{35}Ge_{10}$ Thin Film with the Polarization State of Recording Beam)

  • 박정일;정홍배
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제55권9호
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    • pp.423-428
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    • 2006
  • We have been carried out the two-beam interference method to form the diffraction grating on chalcogenide $AS_{40}Se_{15}S_{35}Ge_{10}$ thin films for Holography Data Storage (HDS). In the present work, we have been formed holographic diffraction gratings using He-Ne laser (632.8nm) under different Polarization state combinations (intensity polarization holography, phase polarization holography). It was obtained the diffraction grating efficiency by 11st order intensity and investigated the formed grating structure using Atomic Force Microscopy (AFM). As the results, it is shown that the diffraction efficiency of (P: P) polarized recording was maximum 2.4% and we found that its value was rather higher than that of other-polarized recordings. From the results, it is confirmed that the efficient holographic grating formation on amorphous chalcogenide $AS_{40}Se_{15}S_{35}Ge_{10}$ films depend on both the spatial variation of intensity and the polarization state of the incident field pattern.

$MgF_2$/As-Ge-Se-S 다층 박막에서의 홀로그래픽 격자 형성 (Holographic grating formation of $MgF_2$/As-Ge-Se-S multi-layer)

  • 나선웅;여철호;박정일;이영종;정홍배
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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    • pp.1042-1045
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    • 2002
  • We have carried out two-beam interference experiments to form holographic gratings on amorphous $MgF_2$/As-Ge-Se-S multi-layer. In this study, holographic gratings have been formed using He-Ne laser(632.8nm). under different polarization combinations. The diffraction efficiency was obtained by +1st order intensity. The maximum diffraction efficiency of As-Ge-Se-S single layer and $MgF_2$/As-Ge-Se-S multi-layer were 0.8% and 1.4%

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2-step Quadrature Phase-shifting Digital Holographic Optical Encryption using Orthogonal Polarization and Error Analysis

  • Gil, Sang Keun
    • Journal of the Optical Society of Korea
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    • 제16권4호
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    • pp.354-364
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    • 2012
  • In this paper, a new 2-step quadrature phase-shifting digital holographic optical encryption method using orthogonal polarization is proposed and tolerance errors for this method are analyzed. Unlike the conventional technique using a PZT mirror, the proposed optical setup comprises two input and output polarizers, and one ${\lambda}$/4-plate retarder. This method makes it easier to get a phase shift of ${\pi}$/2 without using a mechanically driven PZT device for phase-shifting and it simplifies the 2-step phase-shifting Mach-Zehnder interferometer setup for optical encryption. The decryption performance and tolerance error analysis for the proposed method are presented. Computer experiments show that the proposed method is an alternate candidate for 2-step quadrature phase-shifting digital holographic optical encryption applications.

Secret-key-sharing Cryptosystem Using Optical Phase-shifting Digital Holography

  • Jeon, Seok Hee;Gil, Sang Keun
    • Current Optics and Photonics
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    • 제3권2호
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    • pp.119-127
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    • 2019
  • A new secret-key-sharing cryptosystem using optical phase-shifting digital holography is proposed. The proposed secret-key-sharing algorithm is based on the Diffie-Hellman key-exchange protocol, which is modified to an optical cipher system implemented by a two-step quadrature phase-shifting digital holographic encryption method using orthogonal polarization. Two unknown users' private keys are encrypted by two-step phase-shifting digital holography and are changed into three digital-hologram ciphers, which are stored by computer and are opened to a public communication network for secret-key-sharing. Two-step phase-shifting digital holograms are acquired by applying a phase step of 0 or ${\pi}/2$ in the reference beam's path. The encrypted digital hologram in the optical setup is a Fourier-transform hologram, and is recorded on CCDs with 256 quantized gray-level intensities. The digital hologram shows an analog-type noise-like randomized cipher with a two-dimensional array, which has a stronger security level than conventional electronic cryptography, due to the complexity of optical encryption, and protects against the possibility of a replay attack. Decryption with three encrypted digital holograms generates the same shared secret key for each user. Schematically, the proposed optical configuration has the advantage of producing a kind of double-key encryption, which can enhance security strength compared to the conventional Diffie-Hellman key-exchange protocol. Another advantage of the proposed secret-key-sharing cryptosystem is that it is free to change each user's private key in generating the public keys at any time. The proposed method is very effective cryptography when applied to a secret-key-exchange cryptosystem with high security strength.

Optical Encryption Scheme for Cipher Feedback Block Mode Using Two-step Phase-shifting Interferometry

  • Jeon, Seok Hee;Gil, Sang Keun
    • Current Optics and Photonics
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    • 제5권2호
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    • pp.155-163
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    • 2021
  • We propose a novel optical encryption scheme for cipher-feedback-block (CFB) mode, capable of encrypting two-dimensional (2D) page data with the use of two-step phase-shifting digital interferometry utilizing orthogonal polarization, in which the CFB algorithm is modified into an optical method to enhance security. The encryption is performed in the Fourier domain to record interferograms on charge-coupled devices (CCD)s with 256 quantized gray levels. A page of plaintext is encrypted into digital interferograms of ciphertexts, which are transmitted over a digital information network and then can be decrypted by digital computation according to the given CFB algorithm. The encryption key used in the decryption procedure and the plaintext are reconstructed by dual phase-shifting interferometry, providing high security in the cryptosystem. Also, each plaintext is sequentially encrypted using different encryption keys. The random-phase mask attached to the plaintext provides resistance against possible attacks. The feasibility and reliability of the proposed CFB method are verified and analyzed with numerical simulations.

Measurement of a Mirror Surface Topography Using 2-frame Phase-shifting Digital Interferometry

  • Jeon, Seok-Hee;Gil, Sang-Keun
    • Journal of the Optical Society of Korea
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    • 제13권2호
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    • pp.245-250
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    • 2009
  • We propose a digital holographic interference analysis method based on a 2-frame phase-shifting technique for measuring an optical mirror surface. The technique using 2-frame phase-shifting digital interferometry is more efficient than multi-frame phase-shifting techniques because the 2-frame method has the advantage of a reduced number of interferograms, and then takes less time to acquire the wanted topography information from interferograms. In this measurement system, 2-frame phase-shifting digital interferograms are acquired by moving the reference flat mirror surface, which is attached to a piezoelectric transducer, with phase step of 0 or $\pi$/2 in the reference beam path. The measurements are recorded on a CCD detector. The optical interferometry is designed on the basis of polarization characteristics of a polarizing beam splitter. Therefore the noise from outside turbulence can be decreased. The proposed 2-frame algorithm uses the relative phase difference of the neighbor pixels. The experiment has been carried out on an optical mirror which flatness is less than $\lambda$/4. The measurement of the optical mirror surface topography using 2-frame phase-shifting interferometry shows that the peak-to-peak value is calculated to be about $0.1779{\mu}m$, the root-mean-square value is about $0.034{\mu}m$. Thus, the proposed method is expected to be used in nondestructive testing of optical components.

$MgF_{2}/As_{40}Ge_{10}Se_{15}S_{35}$ 다층박막에서 편광상태에 따른 회절효율 특성 (Characteristics of the Polarization Dependence Holographic Diffraction Efficiency using the $MgF_{2}/As_{40}Ge_{10}Se_{15}S_{35}$ Multi-Layer)

  • 이정태;여철호;신경;이기남;김종빈;정홍배
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 춘계학술대회 논문집 디스플레이 광소자분야
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    • pp.127-130
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    • 2003
  • We have carried out two-beam interference experiment to form holographic grating on amorphous $As_{40}Ge_{10}Se_{15}S_{35}$ single-laver, $MgF_{2}/As_{40}Ge_{10}Se_{15}S_{35}$ muliti-layer. In this study holographic grating formed using He-Ne laser(632.8nm) under different polarization state(intensity, phase polarization holography). The diffraction efficiency was obtained by first order intensity. The maximum diffraction efficiency of $As_{40}Ge_{10}Se_{15}S_{35}$ single-laver was 0.8% and The maximum diffraction efficiency of $MgF_{2}/As_{40}Ge_{10}Se_{15}S_{35}$ multi-layer(multi-layer I, multi-layer II) were 1.4% and 3.1%.

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