Abstract
We demonstrate the design and fabrication of multichannel fibre Bragg gratings (FBGs) with aperiodic channel spacings. These will be suitable for the suppression of specific spectral lines such as OH emission lines in the near infrared (NIR) which degrade ground based astronomical imaging. We discuss the design process used to meet a given specification and the fabrication challenges that can give rise to errors in the final manufactured device. We propose and demonstrate solutions to meet these challenges.
Highlights
There is a demand for multichannel filters for OH emission filtering [1] of Near InfraRed (NIR) wavelengths collected from ground telescopes [2]
We have examined a range of applications that require very specific grating spectral and delay profiles [22, 23] including OH emission line suppression for astrophysics applications which we focus on here
The designed gratings are fabricated with a setup that uses an acoustic optical modulator (AOM) to modulate a beam generated by a 100 mW, 244 nm frequency doubled argon ion laser
Summary
There is a demand for multichannel filters for OH emission filtering [1] of Near InfraRed (NIR) wavelengths collected from ground telescopes [2]. The current state of the art of grating fabrication focuses on increased the fidelity between an expected design and the fabricated device [18] and on characterisation of the fibre and grating to enable fabrication of accurate complex arbitrary profile long gratings [19, 20]. Such gratings have tight constraints in terms of maximum allowed deviation from requirements with respect to wavelength and grating strength. This research attempts to underpin the sources for errors observed after fabricating multichannel gratings and establishes methods to mitigate such errors through the fabrication process
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
