Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effect of wavefront distortions. It is used in astronomical telescopes and laser communication systems to remove the effects of atmospheric distortion. An AO system basically consists of three main components, a wavefront sensor, a wavefront corrector and a control system. A new wavefront sen...

Nearly 60 years ago, Hanbury Brown and Twiss [R. Hanbury Brown and R. Q. Twiss, Nature 178, 1046 (1956)] succeeded in measuring the 30 nrad angular diameter of Sirius using a new type of interferometry that exploited the interference of photons independently emitted from different regions of the stellar disk. Its basis was the measurement of intensity correlations as a function of detector spac...

We investigated the feasibility of using nulling interferometry techniques in the stratosphere to search for extra-solar planets. Studies have shown wavefront distortions from atmospheric turbulence to be too large to obtain clear ground-based images. Wavefront errors caused by atmospheric turbulence in the stratosphere are on the scale of 1 angstrom [4], however, the level of the wavefront err...

optical interferometry is being used as an efficient tool to analyse smooth surfaces for more than a century. although, due to introduction of novel computer assisted analyzing techniques and array detectors, like ccd, the speed and the precision of processing have been increased tremendously, but the main equation involved is not changed. the main equation is the intensity distribution in the ...

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The alignment of the Laser Interferometer Gravitational-wave Observatory (LIGO) using the Global Positioning System (GPS) is described. The LIGO project is designed to detect gravitational waves from astrophysical sources by laser interferometry. There are two sites separated by 3002 km that will be operated in coincidence. At each, site laser beams propagate in two orthogonal 4 km long evacuat...

Related Articles Implementation of moiré-schlieren deflectometry on a small scale fast capillary plasma discharge J. Appl. Phys. 111, 103301 (2012) Simultaneous translational temperature measurements of different atomic species in plasma flows using scanning Fabry-Perot interferometry Rev. Sci. Instrum. 83, 053111 (2012) Quantitative measurement of hard x-ray spectra for high intensity laser pr...

Laser interferometry is an extensively used diagnostic for plasma experiments. Existing plasma interferometers are designed on the presumption that the scene and reference beam path lengths have to be equal, a requirement that is costly in both the number of optical components and the alignment complexity. It is shown here that having equal path lengths is not necessary, instead, what is requir...

Schlieren interferometry is found to be an alternative tool for temperature measurement during thermoplastic laser welding with regard to methods based on thermocouples or optical pyrometers. In fact, these techniques are not easily applied when materials to be processed have reduced thickness, negligible heat conduction, and low emissivity, as is the case of welding high-density polyethylene f...

A room temperature operating Vertical External Cavity Surface Emitting Laser is applied around 1550 nm to intracavity laser absorption spectroscopy analyzed by timeresolved Fourier transform interferometry. At an equivalent pathlength of 15 km, the high resolution spectrum of the semiconductor disk laser emission covers 17 nm simultaneously. A noise equivalent absorption coefficient at one seco...