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Holography - Optical memory - Short pulse generation - choh/degree/Laser_Applications/... · PDF file · 2016-08-29- Optical memory - Short pulse generation - Nonlinear optics.

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  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    - Holography- Optical memory- Short pulse generation- Nonlinear optics

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    (Holography)Hologram : whole message

    - 1948, Dennis Gabor : (1972 )- 1960, Michigan , E. Leith, J. Upatnieks : ,

    off-axis .- 1960, , Denisyuk : ( ),

    . - 1970, Benton : (),

    , . - 1977, Cross :

    D. Gabor

    Denisyuk

    Benton

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    1.

    2.

    r1r2

    r3

    )}({exp rkti rr

    film

    http://km.naver.com/list/view_detail.php?dir_id=50201&docid=46501http://km.naver.com/list/view_detail.php?dir_id=50201&docid=46501

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    ()

    1.

    laser beam

    film

    mirror

    2.

    film

    mirror

    .

    virtual image

    object

    .

    http://km.naver.com/list/view_detail.php?dir_id=50201&docid=46501http://km.naver.com/list/view_detail.php?dir_id=50201&docid=46501

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    1.

    2.

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    Holography

    This 10x8 inch two-step full color reflectionholographic stereogram of an Acura NSX was madeusing a single laser wavelength (647 nm), anda single high-resolution photographic plate.Color was produced using the "In-Situ" color controltechnique developed by Spatial Imaging alum Julie Parker.Data courtesy of Alias Research and HondaR&D Company.

    Here is a large-scale one-step holographic stereogram.The film measures 1 x 1 meters, and the image volumeoccupies approximately 1 meter of depth. This hologramwas produced in conjuction with research done forGeneral Motors Corporation in 1991. It is composed of1000 separate exposures, and displays a 45 degreeviewing angle.

    - Display(3 , TV, Head up display, )

    - Interferometry(, , , , )

    - Holographic optical memory- Pattern recognition- Diffractive optical elements(DOE)- , ( )- , ,

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    Capacity(

    Gbit/in

    2)

    10-1

    10

    1

    1980 1990 2000 2010

    (Products)

    PC(Phase change)

    MO(Magneto-Optic)

    Mixed

    CD ROM(650MB)

    DVD ROM(4.7GB*2)

    ASMO

    5.25MO(1X)

    5.25MO(2X)

    1st DVD RAM2.6GB*2

    MAMMOS

    HD DVD~1.5GB*2

    IOPM

    Holography

    5.25MO(8X)

    CD ROM(650MB)PD

    (650MB)

    2nd DVD RAM4.7GB*2

    3rd DVD RAM~15GB*2

    3D multi-layer

    102

    (optical memory)

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    1. CD(compact disc), DVD , , , ,

    http://imagesearch.naver.com/search.naver?where=dt_iphoto&query=cd&sort=0&scp=0&c=2&qt=df&xc=&top=1

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    pit land =>

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    CD-RW

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    2. Holographic optical memory

    - CD/DVD

    - :

    (Photorefractive crystal)

    (photorefractive polymer)

    (photochromic polymer)

    (Photoisomerization polymer)

    (Spectral hole burning material)

    - : , ,

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    Ar+ ion laser

    /2 WP

    PBS

    BE SLM spatialfilter

    CCD

    reference beam

    image beam

    polymer

    shutter

    /2 WP

    camera

    (PDR1)

    514.5 nm

    computer

    Holographic data storage

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    Original images and reconstructed images in PDR1 film

    < Original Images > < Reconstructed Images >

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    HDDS (holographic digital data storage)

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    Photorefractive Crystal VHDDS(Volume holographic digital data storage)- IBM

    Holographic data storage HM-100 -Holoplex

    Input beam(signal arm)

    SLM

    Signal Beam

    Input beam(reference arm)

    Recording/Readout Head

    Lens of high NA

    ReferenceBeam

    Axis of disk rotation

    CCD

    HolographicDisk Shift

    MationOutput beam(reconstrnctionarm)

    z

    x

    L

    s

    za

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    Short pulse generation- Q switching- Mode locking

    1. Q switching: sudden switching of the laser cavity Q from a low value to a high value

    full mirror output coupleractive medium

    Switching method- Rotating mirror- Electro-optic switching- Saturable absorber

    Pulse width ~ 10 ns

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    Rate equations

    IcgINc

    dtdI

    t= 2)(

    222122 )( KNIN

    hdtdN

    +=

    Put, tNch

    Ix=

    1

    2

    NNy =, , tcgt=

    xyxyddx

    = )1(

    y x

    y

    x

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    2. Mode locking: locking the phases of longitudinal modes by modulating the cavity Q

    Modulation method- Acousto-optic modulation- Electro-optic modulation- Saturable absorber

    Pulse width ~ 10 fs full mirror output coupleractive medium

    modulator

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    Acousto-optic modulator: photoelastic effect

    PZT(piezo-electric transducer)

    acousto-optic cell

    Electro-optic modulator: Electro-optic effect

    ACpolarizer

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    )sin()sin(),( mmmmmm tzkEetzE +=r

    Mode locking pulse

    Electric filed of m-th longitudinal mode

    where, L

    mkm

    = ckmm =,

    Assume, 0=m

    Total electric field in the cavity

    )}(cos),()(cos),({2

    ),( 0)(

    0)(0 ctzktzActzktzAtzE NN +=

    +

    where, N : number of modes

  • Nonlinear Optics LabNonlinear Optics Lab. . HanyangHanyang Univ.Univ.

    Mode-locked laser system and mode locking pulse

    fs Ti:sapphire laser system

    Mode-locked pulse

    2L/c

    Pulse width : 2L/cN

    - Holography- Optical memory- Short pulse generation- Nonlinear optics

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