Hybrid electro-optic visible multi-telescope beam combiner for next generation FIRST/SUBARU instruments

G. Martin, M. Foin, S. Phatak, M. Beldjoudi, A. Billat, C. Cassagnettes, A. Coste, N. Courjal, M. Lallement, K. Barjot, N. Cvetojevic, S. Vievard, E. Huby, S. Lacour, V. Deo, O. Guyon

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

FIRST (Fibered Imager foR a Single Telescope instrument) is an instrument that enables high contrast imaging and spectroscopy, thanks to a unique combination of sparse aperture masking, spatial filtering by single-mode waveguides and cross-dispersion in the visible. In order to increase the instrument's stability and sensitivity, we propose an active hybrid photonic beam combiner. The device consists on a 5T integrated optics beam combiner. The idea is to split the architecture in two parts: A first part, concerning input beam splitting and active phase modulation, requiring relatively simple optical circuits (Y junctions and straight waveguides) is obtained in an electro-optic crystal (Lithium Niobate). A second part, where the complex beam recombination of all the split inputs is achieved (for N inputs, N(N-1)/2 recombinations). This stage implies many waveguide crossings, bendings and lengthy waveguides. Therefore, a high transmission, high confining glass is used. In both cases, classical lithography and ion in-diffusion techniques are used to fabricate the waveguides. Both stages have been optimized in terms of mode matching and single mode spectral bandwidth. They have been assembled together and with input/output fibered V-grooves. The work presented here consists on the characterization of the hybrid 5T beam combiner on the optical bench simulator of the FIRST/SUBARU instrument that is developed at LESIA. We will present results in terms of transmission, polarization and active phase modulation, showing that with relative low voltages, active fringe scan is achieved directly on-chip, at frequencies only limited by the readout time of the camera.

Original languageEnglish (US)
Title of host publicationAdvances in Optical and Mechanical Technologies for Telescopes and Instrumentation V
EditorsRamon Navarro, Roland Geyl
PublisherSPIE
ISBN (Electronic)9781510653573
DOIs
StatePublished - 2022
EventAdvances in Optical and Mechanical Technologies for Telescopes and Instrumentation V 2022 - Montreal, Canada
Duration: Jul 17 2022Jul 22 2022

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume12188
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X

Conference

ConferenceAdvances in Optical and Mechanical Technologies for Telescopes and Instrumentation V 2022
Country/TerritoryCanada
CityMontreal
Period7/17/227/22/22

Keywords

  • electro-optic modulation
  • FIRST Instrument
  • glass waveguides
  • integrated optics
  • Lithium Niobate
  • Subaru Telescope
  • visible interferometry

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Fingerprint

Dive into the research topics of 'Hybrid electro-optic visible multi-telescope beam combiner for next generation FIRST/SUBARU instruments'. Together they form a unique fingerprint.

Cite this