학술논문
Development of an integrated near-IR astrophotonic spectrograph
Document Type
Working Paper
Source
SPIE 11451, Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation IV, 114516L (13 December 2020)
Subject
Language
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.
Comment: 7 pages, 7 figures, Published in the proceedings of SPIE Astronomical Telescopes + Instrumentation, 2020
Comment: 7 pages, 7 figures, Published in the proceedings of SPIE Astronomical Telescopes + Instrumentation, 2020