Why Detectors are Important Don Figer RIDL, RIT
Dec 19, 2015
Why Detectors are Important
Don FigerRIDL, RIT
2IT Collaboratory 2009 Research Symposium
This is Why Detectors are Important
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TRANSLATION: With better detectors, you make more discoveries, solve more problems, cure more people, identify more threats, reduce war, and manage resources more effectively.
3IT Collaboratory 2009 Research Symposium
Make Discoveries: Galactic Center
El Centro Galáctico: 1967-1994
Gatley/NOAO/KPNO, (PtSi array) G. Neugebauer & E. E. Becklin/Caltech (PbS)
4IT Collaboratory 2009 Research Symposium
The Galactic Center: Closeup
Forrest, Pipher, & Stein 1986, IRTF, 32x32 InSb
5IT Collaboratory 2009 Research Symposium
”Imaging” Detectors for non-imaging Applications: Spectroscopy
Figer et al. 2000
6IT Collaboratory 2009 Research Symposium
Cure People
7IT Collaboratory 2009 Research Symposium
Identify Threats
• Threats to national space security assets– inter-continental ballistic missiles– anti-satellite kill vehicle– orbital debris– laser blinding systems
• Threats to people/homeland– bio/chem hazards– dirty bombs
8IT Collaboratory 2009 Research Symposium
Reduce War
• Monitoring– treaty compliance– nuclear proliferation– arms buildup
• Enabling pre-emptive strikes• Enabling conflict resolution
9IT Collaboratory 2009 Research Symposium
Manage Resources
Water
Vegetation
Forests
Atmosphere (e.g. ozone)
10IT Collaboratory 2009 Research Symposium
Enter Quantum-LimitedImaging Detectors
11IT Collaboratory 2009 Research Symposium
Quantum-Limited Imaging Detectors
• These detectors are limited by the information carried by a photon.– existence– wavelength– polarization
• The task to realize these detectors is difficult. It’s “easier said than done…..”
12IT Collaboratory 2009 Research Symposium
Read NoiseThe Importance of Read Noise in Imaging
Images of the Arches cluster near the Galactic center, based on real data obtained with Keck/LGSAO. Each image has synthetic shot noise and increasing read noise (left to right and top to bottom: 0, 5, 10, 100 electrons).
13IT Collaboratory 2009 Research Symposium
Better Detector or Bigger Telescope
Effective Telescope Size vs. Read Noise
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60
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Read Noise (electrons)
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This plot shows a curve of constant sensitivity for a range of telescope diameters and detector read noise values in low-light applications. A 30 meter telescope and zero read noise detector would deliver the same signal-to-noise ratio as a 60 meter telescope with current detectors.
14IT Collaboratory 2009 Research Symposium
James Webb Space Telescope
15IT Collaboratory 2009 Research Symposium
Hunt for Dark Energy
Brown 2007, PhD Thesis
16IT Collaboratory 2009 Research Symposium
Finding Earth-like Planets
Clampin 2005, SDW
17IT Collaboratory 2009 Research Symposium
Imaging at Night
18IT Collaboratory 2009 Research Symposium
Traditional Low-Light Limitations
Integration TimeShort Infinite
19IT Collaboratory 2009 Research Symposium
LIDAR+Photon Counting Simulation
3D Point Cloud Integrated 2D Intensity Image Utilizing Laser forIllumination
LIDAR Imaging
Full Moon Half Moon New MoonGm-APD as a Photon CounterUnder AmbientIllumination
20IT Collaboratory 2009 Research Symposium
Key Detector Characteristics
DarkCurrentDark
Current λ/Δλλ/ΔλQEQE λλReadNoise
ReadNoise ΔtΔt
Quantum-Limited Imaging Detector
PP
EarthSystemScience
EarthSystemScience
BiomedicalImaging
BiomedicalImaging
HomelandSafety
HomelandSafety DefenseDefense
21IT Collaboratory 2009 Research Symposium
Challenges
22IT Collaboratory 2009 Research Symposium
QLID Technology Challenges
• Non-standard (non-CMOS) fabrication• Cold temperature operation (10’s mK?)• False counts (afterpulsing)• Long dead times• Low spectral resolution• Polarization?
23IT Collaboratory 2009 Research Symposium
Challenges=$$$
24IT Collaboratory 2009 Research Symposium
George Smith and Willard Boyle Invent CCDs at Bell Labs in 1969
25IT Collaboratory 2009 Research Symposium
The First Astronomical CCD Image
In 1973, the American company Fairchild Imaging developed their first commercial CCD. Consisting of 100 x 100 pixels, it was used in 1974 to produce the first astronomical photo ever taken by a digital camera. It consisted of an image of the Moon captured using a 20-centimetre telescope, by Jim Janesick (http://astro-canada.ca/_en/a2310.html)
26IT Collaboratory 2009 Research Symposium
Summary
• Detectors play a crucial role in high performance photon sensing instruments.
• Some of the most demanding future applications require new advanced detectors.
• We are at the cusp of the era of quantum-limited imaging detectors