The demand for space-based Earth observation data is growing, particularly the deployment of novel sensors and remote sensing systems that provide increased coverage (spectral, spatial, temporal), improved data availability and also capacity for data customization (e.g. flexible missions).
This enhanced remote sensing requires new imaging solutions that reduce development and manufacturing times while at the same time reducing the size and weight of space-born optical devices and, as a result, the costs of space launch and operations.
Meta-optical surfaces for Shortwave infrared (SWIR) and thermal infrared (TIR) spectral ranges promise to replace bulky and heavy glass objectives with lightweight, thin film-based optics. As an example, existing SWIR and TIR lenses weigh up to 8kg. In comparison, meta-optical surfaces can weigh only a few tenths of a gram and are limited solely by the weight of the supporting substrate and frame.
Furthermore, the new meta-material photonics technology allows for the easy development of custom, multi-spectral and multi-polarization optical system designs tailored to the particular space mission/user requirements. On the other hand, the integration of meta-material optical elements with SWIR and TIR sensors is yet a challenging task when designing space systems payloads.
The Centre aims to provide breakthrough advances in space-based imaging by harnessing the advances in nanofabrication of optical materials.
Active Projects
Engineering study on the feasibility of using novel meta-optical elements in the design of multi-spectral/multi-polarization SWIR imagers for space applications
Institutions: Australian National University.
Project supported by the European Space Agency (ESA)
This project will undertake space qualified testing of meta-optical elements and provide reports on radiation testing, vibration and thermovacuum cycling testing. These tests are needed to establish if the meta-optics technology can fly in space.
Multi-Spectral and Polarisation Imaging with Ultra-Light Nano-Optics for Smarter Satellites
Institutions: Australian National University
The project expects to develop novel imaging principles based on specially tailored ultra-thin optical films containing millions of nanoscale elements to facilitate real-time measurement and efficient onboard processing of both the spectral characteristics and light polarization, for direct spectral and polarization imaging from smallsat space platforms.
These outcomes can provide the technological foundation for the next-generation imaging from space with capabilities in the identification of otherwise invisible structures, both on the Earth surface and underwater, and thereby provide game-changing benefits for diverse applications.
The imaging techniques underpin the capabilities in space based surveillance and monitoring across the range of domains, spanning from earth based to underwater locations. Of particular importance is the ability to capture and process in real-time the optical spectral characteristics, in the visible or infrared ranges, which can enable the identification of otherwise ‘invisible’ objects and their characteristics.
Furthermore, the imaging of optical polarization information can facilitate not just the reduction of glare from water surfaces, but deliver the crucial capability such as seeing objects beneath the surface and determining aerosol properties.
Enhanced and selective IR detection with thin plasmonic layers
Institutions: University of Technology Sydney
This project is developing ultra-thin pixels of layers such as graphene and silicon carbide imaging to enhance IR absorption, allowing detection and imaging at very low intensities. These pixels can also be selective to particular characteristics of the light, like polarisation.
Design and engineering of an integrated device which can perform ultra-secure encryption using light as the source of information.
Institutions: University of Technology Sydney
This project consists of three components; a source from a flat (2D) material hexagonal boron nitride (hBN) which can produce individual photons on demand, a compact optical setup and enclosure used to analyse and manipulate these photons, and a unique encryption algorithm utilised to efficiently perform the quantum encryption. Integration of these components will allow for a portable, robust, and readily integrated means of performing ultra-secure cybercommunications that can be integrated into existing orbital satellites to provide a ground-to-space link in order to provide a powerful and secure improvement for the telecommunications industry.
Using light as an information carrier has inherent advantages when operating over long distances, as light has very little interaction with the surrounding medium it travels through. By utilising orbital space satellites to act as receivers and transponders, quantum cyber-communications can be performed over phenomenally long distances of over 1000 kilometres. This translates to the possibility of intercontinental ultra-secure communication between two parties handling sensitive information.
Passive IR sensors and imaging FPAs
Institution: University of Western Australia
Passive IR sensors and imaging FPAs are key elements of space-based intelligence, surveillance and reconnaissance (ISR) systems, earth observation (EO), and space situational awareness (SSA), which usually requires operation in the atmospheric transmission windows of short-wave IR (SWIR, 1.5 – 2.5 micron wavelength), mid-wave IR (MWIR, 3 – 5 micron wavelength) or long-wave IR (LWIR, 8 – 12 micron wavelength).
For such demanding and high performance systems, HgCdTe is the detector material-of-choice due to its unsurpassed optoelectronic properties and its unique ability to be tailored to operate across any of the IR wavelength bands. In addition, the added capability of MEMS-based passive multi/hyperspectral imaging at IR wavelengths enables target fingerprinting and identification in systems that can be deployed with cost-efficient, low-SWaP, small aperture optical instruments.
IR Imaging FPA Technology
Institution: University of Western Australia
We have developed various custom-designed HgCdTe-based IR detector, imaging FPA, and spectroscopic sensor technologies in a range of wavelength bands (SWIR, MWIR, and LWIR) and in various formats for end-users in the defence and aerospace sector. It is rather difficult to specify a TRL that covers all of the various capabilities, which can cover various wavelength bands requiring specific sensor technologies and range from a single-pixel detector to a 2-D 320×256 pixel thermal imaging FPA, as shown in the figure above. Thus, the information presented below is a rough estimate.
MWIR thermal imaging sensor capability has been the main focus of MRG technology development (see above figure), and is deemed to be at TRL6, which would require minimal effort to develop to TRL7, although significant effort would be required to extend beyond an array size of 640×512 pixels.
The SWIR and LWIR sensor capability has been at a rudimentary level (TRL3/4) and limited to single detectors and small test arrays, simply due to the lack of funded projects at these wavelengths.