Measure & validate optical fibres for astronomy

Teodor Tichindelean, Global Product Manager, Polymicro Technologies, Molex, commented: “Multimode optical fibre has revolutionised the way astronomers look at stars and other objects in space by enabling highly stable, remotely mounted, multi-object spectrographs. Optical fibres allow the observation of hundreds of objects in the sky simultaneously by transporting light from a telescope to a spectrograph.”

However, light loss in systems employing multimode optical fibres can be manifested as beam spreading, or FRD. Beam spreading produces resolution loss and inconsistent images in spectrographs. To reduce light losses, instrument designers must quantify FRD and minimise its impact prior to developing key components. The optical test bench performs those measurements.

Existing measurements for optical fibre include real-time geometry (1,000 measurements per second), online tensile strength (100,000psi) and optical testing (attenuation and numerical aperture). The Polymicro Technologies optical test bench, custom engineered by Molex, adds the FRD measurement method for optical fibre astronomy applications to that list. Previously, astronomy equipment developers had to take their own individual FRD measurements, but the optical test bench now allows Molex to accurately measure and verify optical fibre samples.

Over the past 10 years, Polymicro Technologies FBP broad spectrum optical fibre has become the accepted standard for fibre system designers, according to Tichindelean. Polymicro Technologies FBP optical fibre is typically used in astronomy applications.

“Optical fibres that are pretested for FRD performance can reduce the time and cost of developing new spectrographs. We use the optical test bench as a diagnostic tool to identify, quantify and potentially minimise sources of FRD and improve fibre and instrument performance," added Tichindelean.