Detectors play a key role in astronomy, since they convert “messengers” coming from astronomical sources (electromagnetic radiation, particles, gravitational waves) into signals which can be analyzed. Their performance are crucial for astronomical observations, which explain the interest of astronomers in pushing the technology development in this field.
Currently, at IASF-Milano R&D projects are ongoing on the following kinds of detectors:
- Microchannel Plate detectors for photon counting, high time resolution imaging
- Detectors for imaging polarimetry based on organic nanostructured coatings
Microchannel Plate detectors
Microchannel plates-based detectors have been for a long time the detectors of choice in many applications requiring imaging with high time resolution and/or photon counting capability.
In principle, MCPs (with an appropriate readout system) can provide:
- very high time resolution: down to 10ps
- high spatial resolution: down to 10 μm
- large sensitive area size: up to 20 cm2
- photon counting capability with virtual zero noise
- gating capability at ns scales
However, their use has been restricted to low flux applications due to well-known drawbacks, mainly the limited lifetime and dynamic range. At IASF Milano, R&D programs have been carried out on MCP detectors for astronomy and solar physics in the UV range (see, for example, METIS).
Recent technology developments in the production of MCPs allowed significant improvements (of two-three order of magnitude) in the lifetime and stability of these devices. With these new characteristics, MCPs are worthy of new studies even for applications with high flux, but new readout systems need to be developed, which is the focus of the current development program.
POSEIDON (POlarization-SEnsitive Imaging Detectors with Organic Nanostructured coatings)
Polarimetry is crucial in providing information that imaging or spectroscopy alone cannot supply, since it gives a clear and unique insight of the physical properties of the environment where the light is originated and propagated.
Funded by the EU ATTRACT call, the main objective of this project is to develop an innovative coating that, added to color imaging cameras, provides polarimetric capability in a selected range of wavelengths. The obtained detection systems will be able to simultaneous measure the two different polarization states of the light at each pixel position, crucial in order to minimize and control the systematic errors which generally affect the polarimetric measures. The coatings is realized by using nanostructured materials sensitive to the polarization of the incident light. By using a bilayer of conjugated polymers oriented one orthogonal to the other, the polarization components of the incident light will be converted into two different colors, according to their polarization, as schematically represented in the figure. In this way the polarization information is converted into a spectral information.
