赤外線高分散ラボ:Laboratory of Infrared High-resolution spectroscopy

about WINERED

Top Overview For observers Gallery Technical detail

About WINERED

WINERED (Warm INfrared Echelle spectrograph to Realize Extreme Dispersion and sensitivity) is a near-infrared high-resolution spectrograph developed by LiH. WINERED is a PI-type instrument, and is installed in the 3.58-meter New Technology Telescope (NTT) at the La Silla Observatory from 2017. WINERED has three distinctive features: warm optics (no cold stop), wide spectral coverage (0.90−1.35 μm), and high sensitivity. WINERED has three observing modes: "WIDE" (R≡ λ/Δ λFWHM=28,000) and "HIRES-Y&J" (R=68,000); the latter employs a specially designed high-blazed echelle grating. HIRES-Y&J modes are going to be in science operation by the middle of 2017.



Instrumental Facts

1. Warm optics with no cold stop

(ⅰ) Optics are at room temperature except for the infrared camera system (camera lenses and an infrared array).
(ⅱ) Beneficial to reduce time and cost for development, alignment, and maintenance.


2. Wide spectral coverage

Achieved by a combination of decent optical design with a cross-dispersed echelle and a large format infrared array (2k x 2k).



3. High sensitivity

<High throughput>

  • Gratings with high diffraction efficiency
  •  - WIDE mode: replica echelle grating by Newport Co. (~83%), VPH cross-disperser (~86%).
     - HIRES-Y&J modes: high-blazed echelle gratings by Canon Inc. (>70%), VPH cross-dispersers (~90%).
  • Extremely-low reflection BBAR: R < 0.5% per lens surface.
  • The minimum number of optical elements: no-use of white pupil optics.
  • High Q.E. of an array: 1.7μm cut-off HAWAII-2RG (~86% @1.23μm).

  • <Low noise>

  • Low readout noise: σr= 5.3 e- (NDR=32). Low-dark noise: σ d < 2 e- (900sec)
  • Suppressed ambient thermal background (0.05e- /sec/pix @280 K) with custom thermal-cut filters .

  • 4. PI-type spectrograph

  • Compact [1.8m(L) x 1.1m(W) x 1.0m(H)] and light weight [~250kg].
  • Attachable to any telescopes with a Nasmyth focus (slower than f/11).