F: excess noise factor F = 1.4 M: mean gain

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

http://www.iac.es/index.html

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


Ocam and CCD220


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


0.32e 1300 fps Noise Histogram


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


Measurement of Dark and multiplication gain G

GTSLnTNLn darkd )())((

Statistics from 1000 dark imagesSdark : dark signalT : thresholdG : multiplication gainN : fraction of pixels above T


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


ESO WFS camera based on the Ocam technology.

OCam2: WFS camera for GrantecanDelivery of 2 systems Nov 2010

Ocam technology in Europe

http://upload.wikimedia.org/wikipedia/commons/0/0d/Roque_z04.jpg

http://www.iac.es/index.html


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


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


ExhibitionBooth 306

www.firstlight.fr

F: excess noise factor F = 1.4 M: mean gain

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