Dual-Channel Design
DMD-MOS features purpose-built imaging and spectral channels that are used together to obtain spectroscopic data from the observed targets.
Mechanical Design
Our design consists of two separate channels that share a common field of view incident on the DMD: an imaging channel and a spectral channel. Our design additionally features an integrated calibration system to be used for obtaining spectroscopic calibrations. Throughout the instrument, we use baffling to mitigate stray light. Electronics, like the DMD PCB, are housed in an electronics bay (center bottom). All hardware is mounted atop an aluminum baseplate and is enclosed, with handles used for instrument transportation. The entire enclosed instrument, excluding handles, has a compact footprint with approximate dimensions of 545 mm × 345 mm × 125 mm.
Imaging AND Spectral Channels
The imaging channel consists of a fold mirror, collimating doublet, camera doublet, and a CMOS sensor housed within a Ximea MC031MG-SY camera. This channel serves the important purpose of imaging the telescope field on the DMD, with the resulting images used for creating slit masks for observing specific targets. The spectral channel consists of a traditional spectrograph with a 4-element collimator group, VPH grism, 5-element camera group, and a Ximea xiJ camera featuring a 2k × 2k thermoelectrically cooled scientific-CMOS (sCMOS) GSENSE 2020-BSI sensor.
Key Specs
| Parameter | Value | |
|---|---|---|
| Two Channels | Imaging + Spectral channels of shared field | |
| Input Field (mm × mm) | 14.0 × 10.5 | |
| Input f/# | f/6.8 | |
| Resolution of DMD (micromirror × micromirror) | 1024 × 768 | |
| Wavelength Range (nm) | 400 - 700 (<450 nm not corrected by telescope) | |
| Spectral Resolving Power (@ 550 nm; 2x2 DMD slit) | 1000 | |
| System Efficiency (%) | >40 | |
| Magnification of Spectrograph | 0.47 | |
| Focus of Spectrograph (mm) | 40 | |
| Spectrograph f/# | f/3.3 | |
| Spectrograph Sensor Resolution (px × px) | 2048 × 2048 | |
| Spectrograph Sensor Pixel Pitch (µm) | 6.5 | |
| Magnification of Imaging Channel | 0.5 | |
| Imaging Channel f/# | f/3.4 | |
| Spectrograph f/# | f/3.3 | |
| Imaging Channel Sensor Resolution (px × px) | 2064 × 1544 | |
| Imaging Channel Sensor Pixel Pitch (µm) | 3.4 |