Hello all. In this presentation, I have described the basic principle of Interferometer and gave a brief description of Gravitational Wave that was discovered recently by LIGO (Laser Intereferometer Gravitational Wave Observatory). I hope you have liked it.

1. INTERFEROMETER
TAMOGHNA SAHA
Electronics & Communication Engineering Department
3rd Year

2. Advanced LIGO
 L : Laser
 I : Interferometer
 G : Gravitational wave
 O : Observatory
Louisiana
Washington

3.  WHAT IS AN INTERFEROMETER?
 Device in which EM waves are superimposed in order to extract
information about the wave.
Astronomy Fibre Optics Optical Metrology
Oceanography Seismology Spectroscopy
Quantum Mechanics Nuclear and Particle Physics
Plasma Physics Remote Sensing
 Two waves with the same frequency combine  pattern  phase

4.  WHAT IS GRAVITATIONAL WAVE?
 Ripples in space-time that propagate out at the speed of light
Colossal cosmic collisions and stellar explosions can rattle space-time itself
Einstein first predicted it in his General Theory of Relativity.
After 100 years, his prediction came true. It was detected in 14th September, 2015.

5.  WHAT ARE IT’S SOURCES?

7. HOW ARE THEY DETECTED?

9. WHAT’S SO SPECIAL ABOUT IT?
 Big Bang  13 billion years ago
 To see something 13 billion light years away, we must capture light that
began its journey 13 billion years ago.
 For the first 13,800 years of the universe, light could not break free
 It was DENSE and MURKY.
 Gravitational waves was there.
 We can analyse the property of the early universe.

10. INTERFEROMETRY: APPLICATION IN
ENGINEERING AND APPLIED SCIENCE
 Newton Interferometer is frequently used in the optical industry for testing the
quality of surfaces as they are being shaped and figured.
 In telecommunications, wavelength-division multiplexing depends on filtering
devices that are thin-film etalons.
 Mach-Zehnder Interferometers are the basis of a wide variety of devices,
from RF modulators to sensors to optical switches.
 Ring laser gyroscopes (RLGs) and fibre optic gyroscopes (FOGs) are
interferometers used in navigation systems.
 High precision examination of surface topography in the field of micro-
electronic and micro-optic fabrication.
 Holographic Interferometry is a technique which uses holography to monitor
small deformations in single wavelength implementations. In multi-wavelength
implementations, it is used to perform dimensional metrology of large parts and
assemblies and to detect larger surface defects.

11.  Electronic speckle pattern interferometry (ESPI), also known as TV
holography, uses video detection and recording to produce an image of
the object upon which is superimposed a fringe pattern which
represents the displacement of the object between recordings.
 Interferometric synthetic aperture radar (InSAR) is a radar
technique used in geodesy and remote sensing. Satellite synthetic
aperture radar images of a geographic feature are taken on separate
days, and changes that have taken place between radar images taken
on the separate days are recorded as fringes. The technique can
monitor centimetre-millimetre scale deformation resulting from
earthquakes, volcanoes and landslides, and also has uses in structural
engineering.

12. THANK YOU

13. Is there anything you would like to ask?