The Achromatization of Approximately Monochromatic Interference Fringes by a Highly Dispersive Medium, and the Consequent Increase in the Allowable Path-Difference

1905 ◽  
Vol 40 (16) ◽  
pp. 595
Author(s):  
R. W. Wood
Keyword(s):  
Dispersive Medium ◽  
Path Difference ◽  
Interference Fringes ◽  
Consequent Increase

The Calculation of Energy Flow of Equal Inclination Interference Fringes

2011 ◽  
Vol 105-107 ◽  
pp. 1926-1929
Author(s):  
Jiang Rong Xue ◽  
Xiao Zhang
Keyword(s):  
Light Intensity ◽  
Theoretical Analysis ◽  
Energy Flow ◽  
Focal Length ◽  
Optical Path Difference ◽  
Path Difference ◽  
Optical Path ◽  
Interference Fringes ◽  
Interference Measurement ◽  
Good Agreement

The energy flow of equal inclination interference fringes in Michelson interference measurement is theoretically calculated, and its variation with the optical path difference is also analyzed. When the ratio order of interference radius to focal length of the lens is as low as 10-2 or lower, the energy flow variation with the optical path difference is sinusoidal with period λ/2. Simulation is made via Matlab to verify the theoretical calculation and good agreement has been obtained between theoretical analysis and simulation. The parameters to be measured can be achieved via the record of the change in stripe energy flow, which is superior to the conventional method recording variation in stripe light intensity in good stability and strong anti-jam.

Detection of Laser Direction and Wavelength Using the Unitized Wedge

2011 ◽  
Vol 255-260 ◽  
pp. 2155-2158
Author(s):  
Li Zhang
Keyword(s):  
Detection Method ◽  
Optical Path Difference ◽  
Path Difference ◽  
Optical Path ◽  
Interference Fringes ◽  
Random Direction ◽  
Array Camera

A novel detection method of laser direction and wavelength synchronal is fabricated by combining the four wedges and CMOS array camera. The unitized wedges we designed are composed of the four same wedges, and the joint is non-transparent. When the laser incident in the random direction, we calculate the distance of interference fringes in the four wedges, and deduce laser direction and wavelength. By simulation, it generates the drawings of optical path difference and the mini-distance when the minimum identification angle is 1o. In experiment, when we choose the angle of wedge is 0.01rad (≈0.57o), the distance of interference fringes is 10μm, larger than 8μm in CMOS array camera, so the interference fringes with the 532nm laser can be detected.

Interference Fringes with Long Path Difference Using He–Ne Laser*

1963 ◽  
Vol 53 (3) ◽  
pp. 394 ◽  
Author(s):  
Tadashi Morokuma ◽  
Karl F. Nefflen ◽  
T. R. Lawrence ◽  
Thomas M. Klucher
Keyword(s):  
Path Difference ◽  
Interference Fringes

Quanitative aspects of electron diffraction using electron holography

1995 ◽  
Vol 53 ◽  
pp. 616-617
Author(s):  
E. Völkl ◽  
L.F. Allard ◽  
B. Frost ◽  
T.A. Nolan
Keyword(s):  
Electron Beam ◽  
Electron Diffraction ◽  
Software Package ◽  
Spatial Coherence ◽  
Electron Holography ◽  
Image Intensity ◽  
Interference Fringes ◽  
Complex Image ◽  
The Difference ◽  
Recorded Image

Off-axis electron holography has the well known ability to preserve the complex image wave within the final, recorded image. This final image described by I(x,y) = I(r) contains contributions from the image intensity of the elastically scattered electrons IeI (r) = |A(r) exp (iΦ(r)) |, the contributions from the inelastically scattered electrons IineI (r), and the complex image wave Ψ = A(r) exp(iΦ(r)) as:(1) I(r) = IeI (r) + Iinel (r) + μ A(r) cos(2π Δk r + Φ(r))where the constant μ describes the contrast of the interference fringes which are related to the spatial coherence of the electron beam, and Φk is the resulting vector of the difference of the wavefront vectors of the two overlaping beams. Using a software package like HoloWorks, the complex image wave Ψ can be extracted.

Observation of surface morphology by reflection electron holography

1989 ◽  
Vol 47 ◽  
pp. 536-537
Author(s):  
N. Osakabe ◽  
J. Endo ◽  
T. Matsuda ◽  
A. Tonomura
Keyword(s):  
Phase Shift ◽  
Surface Morphology ◽  
High Sensitivity ◽  
High Energy ◽  
Path Difference ◽  
Transmission Mode ◽  
Electron Holography ◽  
Dynamical Process ◽  
High Vertical Resolution ◽  
Amplification Technique

Progress in microscopy such as STM and TEM-TED has revealed surface structures in atomic dimension. REM has been used for the observation of surface dynamical process and surface morphology. Recently developed reflection electron holography, which employes REM optics to measure the phase shift of reflected electron, has been proved to be effective for the observation of surface morphology in high vertical resolution ≃ 0.01 Å.The key to the high sensitivity of the method is best shown by comparing the phase shift generation by surface topography with that in transmission mode. Difference in refractive index between vacuum and material Vo/2E≃10-4 owes the phase shift in transmission mode as shownn Fig. 1( a). While geometrical path difference is created in reflection mode( Fig. 1(b) ), which is measured interferometrically using high energy electron beam of wavelength ≃0.01 Å. Together with the phase amplification technique , the vertivcal resolution is expected to be ≤0.01 Å in an ideal case.

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