Share Email Print

Proceedings Paper

Interferometers and spectrographs on silicon-platform for astrophysics: trends of astrophotonics
Author(s): Harendra N. J. Fernando; Andreas Stoll; Nick Cvetojevic; René Eisemann; Nuwan Tharanga; Christopher Holmes; Michael Böhm; Martin M. Roth; Roger Haynes; Lars Zimmermann
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

We present results of comprehensive re-design of an arrayed waveguide grating (AWG)-based integrated photonic spectrograph (IPS), using Silica-on-Silicon (SOS) technology, to tailor specific performance parameters of interest to high-resolution (resolving power, R = λ/Δλ= 60,000) exoplanet astronomy and stellar seismology. The compactness, modularity, stability, replicability and small-lightweight-payload of the IPS are a few promising and innovative features in the design of high-resolution spectrographs for astronomy or other areas of sciences. The IPS is designed to resolve up to 646 spectral lines per spectral order, with a wavelength spacing of 25 pm, at a central wavelength of 1630 nm (Hband). The fabricated test waveguides have been stress engineered in order to compensate the inherent birefringence of SOS waveguides. The birefringence values of fabricated test structures were quantified, to be on the order 10-6 (theoretical value required to avoid the formation of ghost-images), through inscription of Bragg-gratings on straight waveguides and subsequent measurement of Bragg-reflection spectra. An interferometer system has been integrated with the SOS-IPS (in the same chip) for the characterization of phase errors of the waveguide array. Moreover, promising results of first fabricated key photonics components to form other complex integrated photonic circuits (IPCs), such as astro-interferometers, using silicon nitride-on-insulator (SNOI) technology are also presented. The fabricated IPCs include multimode interference based devices (power splitter/combiners, optical cross/bar-switches), directional-couplers with varying power ratios, Mach-Zehnder interferometers and an AWG. The first results of annealed, low-hydrogen SNOI based devices are promising and comparable to SOI and commercial devices, with device excess-loss less than 2 dB and under 1 dB/cm waveguide-loss in the IR-wavelength.

Paper Details

Date Published: 28 July 2014
PDF: 9 pages
Proc. SPIE 9151, Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation, 915148 (28 July 2014); doi: 10.1117/12.2056500
Show Author Affiliations
Harendra N. J. Fernando, Leibniz-Institut für Astrophysik Potsdam (Germany)
Andreas Stoll, Leibniz-Institut für Astrophysik Potsdam (Germany)
Nick Cvetojevic, The Univ. of Sydney (Australia)
The Australian Astronomical Observatory (Australia)
René Eisemann, Leibniz-Institut für Astrophysik Potsdam (Germany)
Nuwan Tharanga, Leibniz-Institut für Astrophysik Potsdam (Germany)
Christopher Holmes, Univ. of Southampton (United Kingdom)
Michael Böhm, Univ. Potsdam (Germany)
Martin M. Roth, Leibniz-Institut für Astrophysik Potsdam (Germany)
Roger Haynes, Leibniz-Institut für Astrophysik Potsdam (Germany)
Lars Zimmermann, IHP GmbH (Germany)

Published in SPIE Proceedings Vol. 9151:
Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation
Ramón Navarro; Colin R. Cunningham; Allison A. Barto, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?