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CHARACTERIZATION OF OCAM AND CCD220, THE FASTEST AND MOST
SENSITIVE CAMERA TO DATE FOR AO WAVEFRONT SENSING
---PHILIPPE FEAUTRIER, JEAN-LUC GACH, PHILIPPE BALARD, CHRISTIAN GUILLAUME,
MARK DOWNING, NORBERT HUBIN, ERIC STADLER, YVES MAGNARD, MICHAEL SKEGG, MARK ROBBINS, SANDY DENNEY, WOLFGANG SUSKE, PAUL JORDEN, PATRICK WHEELER, PETER POOL, RAY BELL, DAVID BURT, IAN DAVIES, JAVIER
REYES, MANFRED MEYER, DIETRICH BAADE, MARKUS KASPER, ROBIN ARSENAULT, THIERRY FUSCO AND JOSÉ JAVIER DIAZ GARCIA
[email protected]/06/2010 P. Feautrier - OCam and CCD220 1
P. Feautrier - OCam and CCD220 229/06/2010
F: excess noise factor
F = 1.4M: mean gain
EMCCD: Electron Multiplying CCD
P. Feautrier - OCam and CCD220 329/06/2010
Low read noise of EMCCD is clearly better for white-yellow guide star and better even for red GS if RON of Thick CCD > 2e. Conclusion low RON (~ 0.1e-) is better than higher red response. Reason e2v-EMCCD was chosen.
GS Magnitude.
RON=5
RON=3
RON=2
EMCCDRON=0
Thick CCD
Strehl ratio
RON=5
RON=3
RON=2
EMCCDRON=0
Thick CCD
Strehl ratio
GS Magnitude.
EMCCD low read noise wins
29/06/2010 4P. Feautrier - OCam and CCD220
240 x 240 pixels with 24 µm pitch 8 EMCCD outputs split frame transfer Nominal frame rate: 1500 frames/sec Peltier cooled @ - 45 °C
The e2v CCD220 EMCCD
29/06/2010 P. Feautrier - OCam and CCD220 5
29/06/2010 P. Feautrier - OCam and CCD220 6
Ocam and CCD220
29/06/2010 P. Feautrier - OCam and CCD220 7
0
1 104
2 104
3 104
4 104
5 104
6 104
7 104
8 104
0 500 1000 1500 2000 2500 3000 3500 4000
Res
et d
rain
cur
rent
(e/p
ixel
/fram
e)
Mean signal (adu)
System Gain = Reset current/
frame rate/charge of e =
20 adu/e
System gain e/adu calibration
Multiplication x1Use of reset drain
(per frame) current
measurement embedded in
OCam
29/06/2010 P. Feautrier - OCam and CCD220 8
0.32e 1300 fps Noise Histogram
29/06/2010 P. Feautrier - OCam and CCD220 9
29/06/2010 10P. Feautrier - OCam and CCD220
0
20
40
60
80
100
500 550 600 650 700 750 800 850 900
QE measuredQE specified
QE
mea
sure
d (%
)
Wavelength (nm)
CCD220 Quantum EfficiencyPeak 94% at 650 nm
29/06/2010 P. Feautrier - OCam and CCD220 11
Measurement of Dark and multiplication gain G
GTSLnTNLn darkd )())((
Statistics from 1000 dark imagesSdark : dark signalT : thresholdG : multiplication gainN : fraction of pixels above T
29/06/2010 12P. Feautrier - OCam and CCD220
HV Clock(Volt)
Multiplication Gain x
Dark (e-/pixel/frame) Noise (e-)
Input referred
noise (e-)Amp 0
43.51742 0.0093 870 0.50
Amp 1 1676 0.0094 486 0.29Amp 2
43.41568 0.0084 439 0.28
Amp 3 1558 0.0089 698 0.45Amp 4
44.91292 0.0088 994 0.77
Amp 5 1356 0.0066 443 0.33Amp 6
43.9956 0.0080 525 0.55
Amp 7 881 0.0097 864 0.98Mean 43.9 1379 0.0086 665 0.52
Standard Si CCD220Temperature: -40°C
Frame rate: 1300 fpsGain, dark, noise0 1 2 37 6 5 4
29/06/2010 13P. Feautrier - OCam and CCD220
ESO WFS camera based on the Ocam technology.
OCam2: WFS camera for GrantecanDelivery of 2 systems Nov 2010
Ocam technology in Europe
29/06/2010 P. Feautrier - OCam and CCD220 14
OCam I
OCam2 is the commercial version of Ocam I Improved reliability Improved performances Improved environmental conditions (can work with
air and water temperature up to 40°C) Detector safety (over-illumination) More compact for integration on telescope
P. Feautrier - OCam and CCD220 15
DROP = OCAM + TELESCOPE + ROBOT + Image Analysis
Civil aviation
29/06/2010
Avoid again Concorde crash…
DROPOther applications for OCam2
Runway survey from control tower at 2-3 km
29/06/2010 P. Feautrier - OCam and CCD220 16
29/06/2010 P. Feautrier - OCam and CCD220 17
Test measurement Result UnitMean readout noise ~ 0.52 e-Dark signal at 1300 fps < 0.01 e-/pix/
frameDark signal at 25 fps ~ 0.05 e-/pix/
frameDetector operating temperature -40 °CPeak Quantum Efficiency at 650 nm 94 %Linearity at gain x1000 from 10 to 150 ke <3 %Image area Full Well Capacity at gain x1, 1300 fps 30 Ke-Parallel CTE at gain x1, 1300 fps >0.99995 N/A
Serial CTE at gain x1, 1300 fps 0.99994 N/A
Performances summarry
29/06/2010 18P. Feautrier - OCam and CCD220
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