BATMAN - a DMD based spectrograph at TNG

An INAF (I) / LAM (F) funded project

Work in progess...

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BATMAN is a Digital Micromirror Device (DMD) - based Multi-Object Spectrograph (MOS) demonstrator. Such instrument is capable of accessing a large FOV with very high contrast. The DMD chip, from Texas Instruments, has 2048 × 1080 mirrors with a pitch of 13.68 μm. Such MOEMS was also studied by our team for application in Euclid-NIS. Our optical design is an all-reflective spectrograph design with F/4 on the DMD component. It will have two arms: one for imaging and one for low resolution spectroscopy (R ∼ 250-1000). This demonstrator will allow us to study key parameters such as throughput, contrast and ability to remove unwanted sources in the FOV (background, spoiler sources), PSF effect, spectrum stability on the detector. This study will be conducted in the visible band with possible extension in the near infrared.

A small scale version of BATMAN, called ROBIN, is being built on a bench in order to investigate the mentioned parameters, to study possible unpredicted issues and to optimize the construction of the instrument.

Having a demonstrator like BATMAN mounted on the TNG and performing real sky observations is then of prime importance for characterizing the actual performance of this new family of instruments. We will also investigate the optimal operational procedures to select astronomical objects in crowded fields and to perform data analysis and data handling.
BATMAN will be mounted on the Telescopio Nazionale Galileo during 2012.

View instrument parameters or the efficiencies plot (Table).

Wavelength (nm) vs. Efficiency

Wavelength  Telescope  Focal    Spectrograph  Filter  Grating  CCD   OVERALL
  (nm)                 reducer  mirrors
  400         60%        60%      85%           85%     25%    80%      5%
  450         60%        91%      90%           89%     25%    88%     10%
  500         60%        94%      90%           92%     25%    90%     11%
  550         60%        93%      90%           92%     25%    88%     10%
  600         60%        95%      90%           92%     25%    85%     10%
  650         60%        97%      90%           92%     25%    82%     10%
  700         60%        97%      90%           92%     25%    76%      9%
  750         60%        93%      90%           88%     25%    67%      7%
  800         60%        87%      90%           80%     25%    55%      5%

Involved Institutes and people:

• LAM-Marseille: Frederic Zamkotsian, William Bon, Laurent Martin, Patrick Lanzoni
• IASF-Bologna: Luciano Nicastro, Luca Valenziano, Juri Zuccarelli
• Brera-Merate Observatory: Filippo Zerbi, Marco Riva, Paolo Spano'
• Trieste Observatory: Paolo Di Marcantonio, Ivan Coretti, Roberto Cirami
• TNG: Emilio Molinari, Manuel Gonzalez, Walter Boschin, Hector Perez Ventura, Rosario Cosentino, Adriano Ghedina

References: SPIE 2010

Private area: BATMAN wiki pages, Mail list