Development of an integrated near-IR astrophotonic spectrograph

Abstract

Here, we present an astrophotonic spectrograph in the near-IR H-band (1.45 -1.65 $\mu m$) and a spectral resolution ($\lambda /\delta \lambda$) of 1500. The main dispersing element of the spectrograph is a photonic chip based on Arrayed-Waveguide-Grating technology. The 1D spectrum produced on the focal plane of the AWG contains overlapping spectral orders, each spanning a 10 nm band in wavelength. These spectral orders are cross-dispersed in the perpendicular direction using a cross-dispersion setup which consists of collimating lenses and a prism and the 2D spectrum is thus imaged onto a near-IR detector. Here, as a proof of concept, we use a few-mode photonic lantern to capture the light and feed the emanating single-mode outputs to the AWG chip for dispersion. The total size of the setup is 50$\times$30$\times$20 cm${}^3$, nearly the size of a shoebox. This spectrograph will pave the way for future miniaturized integrated photonic spectrographs on large telescopes, particularly for building future photonic multi-object spectrographs.

7 pages, 7 figures, Published in the proceedings of SPIE Astronomical Telescopes + Instrumentation, 2020

References in corpus (6)

• Arrayed Waveguide Grating Spectrometers for Astronomical Applications: New Results
• Astrophotonic Spectrographs
• Spectrographs for astrophotonics
• Demonstration of an efficient, photonic-based astronomical spectrograph on an 8-m telescope
• First demonstration of OH suppression in a high efficiency near-infrared spectrograph
• Astrophotonics: molding the flow of light in astronomical instruments

Cited by in corpus (3)

• Potential of commercial SiN MPW platforms for developing mid/high-resolution integrated photonic spectrographs for astronomy
• Design, simulation and characterization of integrated photonic spectrographs for Astronomy II: Low-aberration Generation-II AWG devices with three stigmatic points
• An on-chip astrophotonic spectrograph with a resolving power of 12,000