Fringe modulation for an MROI beam combiner

2010 ◽  
Author(s):  
T. M. McCracken ◽  
C. A. Jurgenson ◽  
D. H. Baird ◽  
J. K. Seamons ◽  
K. M. McCord ◽  
...  
Keyword(s):  
Beam Combiner ◽  
Fringe Modulation

scholarly journals Design and Realization of a Compact Efficient Beam Combiner, Based on Liquid Crystal Pancharatnam–Berry Phase Gratings

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 220
Author(s):  
Boxuan Gao ◽  
Jeroen Beeckman ◽  
Kristiaan Neyts
Keyword(s):  
Liquid Crystal ◽  
Berry Phase ◽  
Polarized Light ◽  
Laser Beams ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Beam Combiner ◽  
High Diffraction Efficiency ◽  
High Diffraction ◽  
Crystal Mixture

We demonstrate a laser beam combiner based on four photo-patterned Pancharatnam–Berry (PB) phase gratings, which is compact and has high diffraction efficiency for incident circularly polarized light. The nematic liquid crystal mixture E7 is used as anisotropic material, and the thickness of the layer is controlled by spacers. The beam combiner can bring two parallel laser beams closer to each other while remaining parallel. This work shows the potential to realize components based on flat optical LC devices.

Deep nulling of laser light with a single-mode-fiber beam combiner

2006 ◽  
Vol 45 (12) ◽  
pp. 2749 ◽  
Author(s):  
Pierre Haguenauer ◽  
Eugene Serabyn
Keyword(s):  
Laser Light ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Beam Combiner

LINC-NIRVANA: a Fizeau beam combiner for the large binocular telescope

2003 ◽  
Author(s):  
Tom Herbst ◽  
Roberto Ragazzoni ◽  
David Andersen ◽  
H. Boehnhardt ◽  
Peter Bizenberger ◽  
...  
Keyword(s):  
Beam Combiner

scholarly journals Simulating a dual beam combiner at SUSI for narrow-angle astrometry

2013 ◽  
Vol 36 (1-2) ◽  
pp. 195-221 ◽  
Author(s):  
Yitping Kok ◽  
Vicente Maestro ◽  
Michael J. Ireland ◽  
Peter G. Tuthill ◽  
J. Gordon Robertson
Keyword(s):  
Narrow Angle ◽  
Dual Beam ◽  
Beam Combiner

Grating Beam Combiner.

1982 ◽  
Author(s):  
Michael E. Schroeder ◽  
Kenneth D. Stumpf ◽  
Mary A. Mullahy
Keyword(s):  
Beam Combiner

Segmentation in multi-objects scene based on disparity and fringe modulation analysis

2020 ◽  
Vol 49 (6) ◽  
pp. 20200085
Author(s):  
李小晗 Xiaohan Li ◽  
陈璐 Lu Chen ◽  
周翔 Xiang Zhou
Keyword(s):  
Fringe Modulation

scholarly journals Detection of the Schwarzschild precession in the orbit of the star S2 near the Galactic centre massive black hole

2020 ◽  
Vol 636 ◽  
pp. L5 ◽  
Author(s):  
◽  
R. Abuter ◽  
A. Amorim ◽  
M. Bauböck ◽  
J. P. Berger ◽  
...  
Keyword(s):  
Black Hole ◽  
Reference Frame ◽  
Adaptive Optics ◽  
Galactic Centre ◽  
Massive Black Hole ◽  
Central Mass ◽  
Black Hole Candidate ◽  
Beam Combiner ◽  
Direct Measurements ◽  
Sgr A

The star S2 orbiting the compact radio source Sgr A* is a precision probe of the gravitational field around the closest massive black hole (candidate). Over the last 2.7 decades we have monitored the star’s radial velocity and motion on the sky, mainly with the SINFONI and NACO adaptive optics (AO) instruments on the ESO VLT, and since 2017, with the four-telescope interferometric beam combiner instrument GRAVITY. In this Letter we report the first detection of the General Relativity (GR) Schwarzschild Precession (SP) in S2’s orbit. Owing to its highly elliptical orbit (e = 0.88), S2’s SP is mainly a kink between the pre-and post-pericentre directions of motion ≈±1 year around pericentre passage, relative to the corresponding Kepler orbit. The superb 2017−2019 astrometry of GRAVITY defines the pericentre passage and outgoing direction. The incoming direction is anchored by 118 NACO-AO measurements of S2’s position in the infrared reference frame, with an additional 75 direct measurements of the S2-Sgr A* separation during bright states (“flares”) of Sgr A*. Our 14-parameter model fits for the distance, central mass, the position and motion of the reference frame of the AO astrometry relative to the mass, the six parameters of the orbit, as well as a dimensionless parameter fSP for the SP (fSP = 0 for Newton and 1 for GR). From data up to the end of 2019 we robustly detect the SP of S2, δϕ ≈ 12′ per orbital period. From posterior fitting and MCMC Bayesian analysis with different weighting schemes and bootstrapping we find fSP = 1.10 ± 0.19. The S2 data are fully consistent with GR. Any extended mass inside S2’s orbit cannot exceed ≈0.1% of the central mass. Any compact third mass inside the central arcsecond must be less than about 1000 M⊙.

scholarly journals Astrometry and Photometry of 400 Million Stars Brighter than 18 Mag

1993 ◽  
Vol 156 ◽  
pp. 37-45
Author(s):  
E. Høg
Keyword(s):  
Proper Motions ◽  
Satellite Mission ◽  
Beam Combiner ◽  
Expected Performance ◽  
Ccd Detectors

A satellite mission for accurate astrometry and multi-colour photometry is discussed, similar in principle to the ESA Hipparcos mission and here called theRoemer mission.The limiting magnitude will be aboutV= 18 mag while 13 mag is the limit of the present Hipparcos mission. Luminosities of stars up to 2 kpc away can be obtained, corresponding to a volume 10000 times larger than with Hipparcos. A mission of 5 years will provide an accuracy of 0.1 milli-arcsec at 12th magnitude for positions and parallaxes and 0.05 milli-arcsec for annual proper motions. This is achieved by a satellite using a mosaic of CCD detectors in the focal planes of two beam-combiner telescopes of 0.29 m aperture. The instrument is described and the expected performance with an input catalog of 400 million program stars is given.

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