Research Interests

Wavefront Distortions in Metrology Experiments

I'm interested in both conventional gravitational wave detection and atom interferometry.

Please feel free to email me at ajones@star.sr.bham.ac.uk with any questions about my research. I would be more than happy to discuss it.

Gravitational Waves

Gravitational waves are an entirely new way of observing the universe. These waves are a stretch and squash of something scientists call space-time. These are produced due when massive objects undergo certain types of gravitational accelerations.

Gravitational waves were first observed in 2015, almost 100 years after Albert Einstein's prediction. This is exciting and interesting in it's own right, but it also opens the door to a new era of gravitational wave astronomy.

Up until now all observations of the universe have been with light. This might be radio wave light (called radio wave because it is the same frequency as radio transmissions), visible light or ultraviolet light. With this knowledge scientists have been able to answer a great many questions about the universe, such as:

But there are many unanswered questions. Many physicists hope that by observing universe using gravitational waves will unlock the answers to some of these questions. If you want to know more, see this LIGO page.


Phase

Phase is a property of all waves. Think of waves on the sea, the phase of the wave determines where the crest of the wave is in relation to a point.

If two waves are in phase, then when they interfere they result in a single larger wave. If waves are not in phase, then when they interfere the sea is flat.


LIGO

LIGO is the Laser Interferometer Gravitational-Wave Observatory. The observatory consists of a pair of operational Michelson interferometers. These devices coherently split light along two arms using a beam splitter. The light is then reflected from the end mirrors and interferes when it returns to the beam splitter. The light will have acquired a phase while traveling from the beam splitter to the mirrors and back.

This phase depends on the space-time interval between the mirrors and the beam splitter. When a gravitational wave passes, the space is stretched and squashed differently in each of the arms and the signal can be determined.


Transverse Phase

The phase of light varies along the direction of propagation. However there also exists a variation perpendicular to the beam direction. I am interested in the applications of this for both conventional gravitational wave detectors, like LIGO and also for atom interferometry.


Sources