Mach–Zehnder Optical Reference Beam Interferometry

2017 ◽  
pp. 5-22
Author(s):  
Gregory R. Toker
Keyword(s):  
Reference Beam ◽  
Optical Reference

scholarly journals Linking the FK5 to the ICRF

1998 ◽  
Vol 11 (1) ◽  
pp. 313-316
Author(s):  
F. Mignard ◽  
M. Froeschile
Keyword(s):  
Reference Frame ◽  
Proper Motion ◽  
Harmonic Functions ◽  
Optical Reference ◽  
Precessional Motion ◽  
Precession Constant

Abstract The Hipparcos optical reference frame is compared to the basic FK5 in order to determine the orientation at T0 = 1991.25 and the global spin between the two frames. The components of the spin are significant and suggest a correction the IAU76 value of the precession constant and to a possible non-precessional motion of the equinox of the FK5. The regional errors are analysed with harmonic functions and found to be as large as 150 mas in position and 3 mas/yr in proper motion.

scholarly journals CONFOR: A New Program for Determining the Connection Between Radio and Optical Reference Frames

1990 ◽  
Vol 141 ◽  
pp. 75-76
Author(s):  
V.S. Gubanov ◽  
I.I. Kumkova ◽  
V.V. Tel'Nyuk-Adamchuk
Keyword(s):  
Coordinate System ◽  
Reference Frames ◽  
Fundamental System ◽  
Optical Reference

The program for establishment of a link between the fundamental system FK5 and the radioastronomical coordinate system is described. The program includes photographic and meridian observations of extragalactic radio/optical sources and intermediate reference stars. Observatories of the USSR, GDR and Yugoslavia are participating in the project.

On the Use of Luminescent Single Crystals as Optical Reference Materials

2021 ◽  
pp. 118289
Author(s):  
Patrick Pues ◽  
Sebastian Schwung ◽  
Daniel Rytz ◽  
Thomas Jüstel
Keyword(s):  
Single Crystals ◽  
Reference Materials ◽  
Optical Reference

Optical cryptography using a multifaceted reference-beam hologram

1985 ◽  
Vol 24 (7) ◽  
pp. 933 ◽  
Author(s):  
Thomas G. Chrien ◽  
George M. Morris
Keyword(s):  
Reference Beam

Approaching Terahertz Holography Using the Free Electron Laser

2010 ◽  
Vol 5 (4) ◽  
pp. 98-102
Author(s):  
Yuliya Yu. Choporova ◽  
Maxim G. Vlasenko ◽  
Vasily V. Gerasimov ◽  
Boris A. Knyazev ◽  
Aleksandr A. Nikitin ◽  
...  
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Quantum Cascade Lasers ◽  
Imaging Techniques ◽  
Reference Beam ◽  
Image Sensors ◽  
Terahertz Range ◽  
Terahertz Region ◽  
Series Of Experiments ◽  
Cascade Lasers

Many experiments in the terahertz region have been performed using low-power shot-pulse wideband sources. Appearance of more intense monochromatic terahertz sources (quantum cascade lasers, free electron lasers) and terahertz image sensors enables the implementation of classical variants of optical techniques in the terahertz range. In this paper we describe a series of experiments to demonstrate feasibility of classic holography at the terahertz range using the Novosibirsk free electron laser. Two imaging techniques have been applied for digital hologram recording. A modified MachZehnder interferometer has been fabricated for recording the reference-beam holograms. In-line holograms have been recorded and reconstructed

Phase-shifting digital holography with an unknown reference beam

2021 ◽  
Author(s):  
Roghayeh Yazdani ◽  
Hamidreza Fallah
Keyword(s):  
Digital Holography ◽  
Phase Retrieval ◽  
Reference Beam ◽  
Phase Shifting ◽  
Retrieval Algorithm ◽  
Reference Field ◽  
Digital Holograms ◽  
Noisy Conditions ◽  
Phase Retrieval Algorithm

In digital holography, errors of the reference field degrade the quality of the reconstructed object field. In this paper, we propose an effective method in phase-shifting digital holography in which the reference field does not need to be known and perfect. The unknown complex amplitudes of both reference and object fields are derived simultaneously. The method employs only five digital holograms and a single execution of a phase retrieval algorithm. So, the required measurements and algorithm executions in this method are fewer than those in other methods; it suggests a simpler and faster method. The effectiveness of the suggested method is indicated by simulation, under noise-free and noisy conditions. Moreover, the capability of the method to extract full information about the phase singularities in both fields is demonstrated.

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