Fibre Bragg gratings

Fibre Bragg gratings (FBGs) are optical devices used in optical fibres to filter certain wavelengths propagating along the fibre. This is achieved when the light is made to reflect at a refractive modulation index on the fibre’s core. As a result the grating can reflect light with high efficiency over a narrow wavelength band. This technology has many applications within the field of Astrophotonics, as well as other fields such as communications and optical fibre sensory equipment.

Hexabundle fibres

Hexabundles are a type of hexagonal fibre arrangement where the fibres are either squeezed together so that there are no gaps in between (fused hexabundle) or are held together by a low stress glue (unfused hexabundle). These will replace components in modern multi-fibre systems.

Integrated spectrographs

One approach to the problem of rising cost and complexity in telescopes as their size increases is to feed the fibres into individual spectrographs rather than one huge (and expensive) spectrograph.

Integrated Photonic Spectrograph Schematic

Integrated Photonic Spectrograph Schematic

Integrated Photonic Spectrograph

Integrated Photonic Spectrograph

Orbital Angular Momentum

Orbital Angular Momentum (OAM) has recently been investigated as a fundamental property of photons and has already found a number of applications. In astrophysics, it has been shown that by detecting the OAM of photons scattered from rotating objects, the rate of rotation can be measured.

Photonic lanterns

The photonic lantern has been developed as a solution to the problem of working with single and multimode fibres in conjunction. This is a technology with many potential applications, not only in astrophysics and astronomy.

Planar Waveguides

These waveguides combine the signals from the component telescopes of an interferometry array, which are connected by an optical network.

Laser Frequency Combs

Frequency combs allow astronomers to detect extrasolar planets by comparing the oscillation of the observed star’s line spectrum with a fixed predicted spectrum, mapped using a laser.

Adaptive Optics

The images of most objects picked up by telescopes are badly distorted by the medium in between the source and the receiver. Adaptive optics attempts to correct this.

Artificial Star Generation

A close by reference point is required in order to use adaptive optics technology. If a bright celestial object is nearby, this makes observations much simpler, but normally an artificial “guide star” is required, and is generated by a powerful laser exciting molecules in the upper atmosphere.

Liquid Crystal Polymers

Liquid crystal polymers are used in adaptive optics as the “adaptive” part, as they can be deformed depending on the nature of the correction being made by the system.

Fibre Positioning Technology

Research continues to go into the robotic fibre positioning systems used to move fibres around on the spectroscopy plates to observe the desired area of sky. The AAO produces many fibre positioners for use in instruments across the world, such as OzPoz and ECHIDNA.