A Dedicated e2v-L3Vision CCD for Adaptive Optics Applications

June 2005June 2005 SDW2005 - Dedicated L3CCD for AOSDW2005 - Dedicated L3CCD for AO 11

Mark DowningMark Downing, Norbert Hubin, Markus Kasper, Javier Reyes, Manfred Meyer, Dietrich Baade, Norbert Hubin, Markus Kasper, Javier Reyes, Manfred Meyer, Dietrich Baade European Southern Observatory ESO (European Southern Observatory ESO (http://http://www.eso.orgwww.eso.org))

Paul Jorden, Peter Pool, Sandy Denney, Wolfgang Suske, Kevin Hadfield, David Burt, Pat WheelerPaul Jorden, Peter Pool, Sandy Denney, Wolfgang Suske, Kevin Hadfield, David Burt, Pat Wheelere2v technologies ltd (e2v technologies ltd (http://e2vtechnologies.comhttp://e2vtechnologies.com))

Philippe Feautrier, Eric Stadler, David Mouillet. Philippe Feautrier, Eric Stadler, David Mouillet. Domaine Universitaire LOAG (Domaine Universitaire LOAG (http://www-laog.obs.ujf-grenoble.fr/JRA2http://www-laog.obs.ujf-grenoble.fr/JRA2))

Jean-Luc GACH, Philippe Balard, Christian Guillaume, Olivier Boissin. Jean-Luc GACH, Philippe Balard, Christian Guillaume, Olivier Boissin. Laboratoire d'Astrophysique de Marseille LAM (Laboratoire d'Astrophysique de Marseille LAM (http://http://www.lam.oamp.frwww.lam.oamp.fr))

José Javier Diaz. José Javier Diaz. IAC, Institute of Astrophysics Canary Islands IAC, Institute of Astrophysics Canary Islands ((http://http://www.iac.eswww.iac.es))

Thierry Fusco. Thierry Fusco. ONERA ONERA ((http://http://www.onera.frwww.onera.fr))

Detector WorkshopDetector Workshop June 2005June 2005

A Dedicated e2v-L3Vision CCD for A Dedicated e2v-L3Vision CCD for Adaptive Optics ApplicationsAdaptive Optics Applications

http://www.eso.org/

http://www.eso.org/

http://e2vtechnologies.com/

http://www-laog.obs.ujf-grenoble.fr/JRA2

http://www.lam.oamp.fr/

http://www.lam.oamp.fr/

http://www.iac.es/

http://www.iac.es/

http://www.onera.fr/

http://www.onera.fr/


The NeedThe Need

Residuals after differential

PSF subtraction

PF will detect faint planets close to very bright starsPF will detect faint planets close to very bright stars with luminosity ratios > 10with luminosity ratios > 1055..

Achieved by performing ultra accurate differential measurementsAchieved by performing ultra accurate differential measurements requiring excellent image quality + stability from its AO system.requiring excellent image quality + stability from its AO system.

The WFS Detector is the critical component of this AO systemThe WFS Detector is the critical component of this AO system its performance is paramount not only to the success of PF butits performance is paramount not only to the success of PF but

most 2most 2ndnd generation VLT instruments (e.g. MUSE, HAWK-I) generation VLT instruments (e.g. MUSE, HAWK-I) and future large telescopes such as OWL & TMT.and future large telescopes such as OWL & TMT.

VLT Planet FinderCoronographic image

VLT/NACO


Funding (Catalyst)Funding (Catalyst)

ESO – for next generation of instrumentsESO – for next generation of instrumentsOPTICON - European Infrastructure programOPTICON - European Infrastructure program

Deliver report and devices on a 2-3 year timescale, our profile is:Deliver report and devices on a 2-3 year timescale, our profile is: low risklow risk.. Need guaranteed deliveryNeed guaranteed delivery of devices that meet requirements. of devices that meet requirements.

JRA2:Fast detectors for AO applications: Philippe FeautrierPoster: Zero noise wavefront sensors development within the Opticon european network

Currently available technologies Currently available technologies →→ split frame transfer CCD split frame transfer CCD


1.1. 6x6 pixels/sub-aperture x 40x40 subapertures 6x6 pixels/sub-aperture x 40x40 subapertures 240x240 pixels.240x240 pixels.2.2. VersatilityVersatility: 100% fill factor / 240x240 square grid array of pixels: 100% fill factor / 240x240 square grid array of pixels

Can be used with any type of WFS system; SH, curvature, or pyramid.Can be used with any type of WFS system; SH, curvature, or pyramid.3.3. > 1 kHz frame rate> 1 kHz frame rate to match the increased spatial sampling. to match the increased spatial sampling.4.4. High QE, low RON and dark current (< 1e-/pixel/frame).High QE, low RON and dark current (< 1e-/pixel/frame).

RequirementsRequirements

40x40 SH-WFS (mag~10, RON=1e-)

240x240 pixels

Next Generation

Systems

Sub-apertureseach

6x6 pixels

Present Systems

8x8 SH-WFS


MAD-WFS CCDMAD-WFS CCD

80x80 pixels80x80 pixels

4outputs4outputs

500Hz frame rate500Hz frame rate

RON: 8-6 e/pixelRON: 8-6 e/pixel

QE: 70-80%QE: 70-80%

Road Map of WFS DetectorsRoad Map of WFS Detectors

e2v-CCD-39

NAOS-WFS CCDNAOS-WFS CCD


2x8 outputs2x8 outputs

25-600 Hz frame rate25-600 Hz frame rate

RON: 2.5-6.5 e/pixelRON: 2.5-6.5 e/pixel

QE: 80%QE: 80%

8 outputs

8 outputs

e2v-CCD-50

Stor

eA

rea

Imag

e A

rea

240x

120

24□µ

m

Stor

eA

rea

Imag

e A

rea

240x

120

24□µ

m

Gai

nR

egis

ters

4 Outputs

4 Outputs

Gai

nR

egis

ters

e2v-CCD-220e2v-CCD-220

Future-WFS CCD-220Future-WFS CCD-220


8 L3 outputs8 L3 outputs

0.25-1.2 kHz frame rate0.25-1.2 kHz frame rate

RON: < 1(0.1)e/pixelRON: < 1(0.1)e/pixel

QE: 90%QE: 90%

MAD: Multi-Conjugate Adaptive Optics DemonstratorPoster: We must be MAD: Pushing FIERA to its limits - Roland ReissAndrea Balestra, Claudio Cumani, Christoph Geimer, Javier Reyes, Enrico Marchetti


Optimisation of Shack-Hartman-based wavefront sensor for XAO systemT. Fusco, R. Conan, G. Rousset, M. Nicolle, C. Petit, D. Mouillet, A. Blanc, J.-F. Sauvage, J.-L. Beuzit.

Proc. SPIE Int. Soc. Opt. Eng. 5490, 1155 (2004).

Low RON vs High Red QELow RON vs High Red QE Compare CCDs with low RON < 1e to CCDs with better red Compare CCDs with low RON < 1e to CCDs with better red

QE but higher RON.QE but higher RON. Guided by simulations by Thierry Fusco for VLT PFGuided by simulations by Thierry Fusco for VLT PF Asked to investigate two detectors:Asked to investigate two detectors:

CCD1 (L3Vision CCD)CCD1 (L3Vision CCD) Good blue QE over 450-700nm Good blue QE over 450-700nm RON = 0 & 1e-, but RON = 0 & 1e-, but 2 multiplication gain noise.2 multiplication gain noise.

CCD2 (conventional but thick 450 CCD2 (conventional but thick 450 µµm fully depleted CCD)m fully depleted CCD) High QE over 450-1000nm.High QE over 450-1000nm. RON ~ 2, 3 & 5e-RON ~ 2, 3 & 5e-

For QE alone, limit. mag. of CCD2 is better by:For QE alone, limit. mag. of CCD2 is better by: O.1 for yellow GS.O.1 for yellow GS. O.5 for red GS.O.5 for red GS.

Dichroic

λ

QE

CCD1

CCD2

∆∆mm


CCD1- L3CCD WinsCCD1- L3CCD Wins

However, need to look at total picture – QE and RON.However, need to look at total picture – QE and RON. Lower RON (~ 0.1e-) better than higher red QE even for red GS.Lower RON (~ 0.1e-) better than higher red QE even for red GS. Reason e2v-L3Vision chosen.Reason e2v-L3Vision chosen.

MPE CCD

L3CCD

Strehl ratio

GS Magnitude.

Strehl ratio

GS Magnitude.


StoreArea

Image Area

240x12024□µm

StoreArea

Image Area

240x12024□µm

OP 1

OP 2 GainRegisters

OP 3

OP 4 GainRegisters

OP 8GainRegisters

OP 7

OP 6GainRegisters

OP 5

The DesignThe DesignMetal ButtressedMetal Buttressed

22ΦΦ 10 Mhz Clocks 10 Mhz Clocksfor fast image to store for fast image to store

transfer rates.transfer rates.

8 L3Vision Gain 8 L3Vision Gain Registers/OutputsRegisters/Outputs..

Each 15Mpix./s.Each 15Mpix./s.

Store slantedStore slanted to allow room for to allow room for multiple outputsmultiple outputs..

Split frame transfer 8-output Split frame transfer 8-output back-illuminated e2v L3Vision CCD.back-illuminated e2v L3Vision CCD.


Improve Red QEImprove Red QE

Good red QE important for red natural GS; especially for PF.Good red QE important for red natural GS; especially for PF. Plan to have split wafer run in std Si and deep depletion.Plan to have split wafer run in std Si and deep depletion. First time L3Vision produced in deep depletion Silicon.First time L3Vision produced in deep depletion Silicon.

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

500 600 700 800 900 1000 1100

nm

QE

e2v Deep Depletion

QE

λ

Std L3Vision


Rayleigh LG Systems:Rayleigh LG Systems: work by Rayleigh back-scatter of laser work by Rayleigh back-scatter of laser

light from water molecules.light from water molecules. Advantage - eAdvantage - enables use of pulsed lasers:nables use of pulsed lasers:

Commercially available.Commercially available. Powerful.Powerful. Cheap - more photons per Euro.Cheap - more photons per Euro.

Requires:Requires: Exposure times of ~ 6.6 Exposure times of ~ 6.6 µµs (2km x 3.3 s (2km x 3.3 µs/µs/km)km) Fast shutter open/close times of ~ Fast shutter open/close times of ~ µµss High extinction ratios (open/close sensitivity)High extinction ratios (open/close sensitivity)

> 10> 104 4 to block large back-scatter ( to block large back-scatter ( Height Height -2-2) ) at low altitudes.at low altitudes.

Solution → Electronic Shuttered CCD.Solution → Electronic Shuttered CCD. Additional design study to deliver 2 devicesAdditional design study to deliver 2 devices

Bonus no smearing → transfer image when shutter Bonus no smearing → transfer image when shutter closed.closed.

Add an Electronic ShutterAdd an Electronic Shutter

20 km altitude

2 km

Rayleigh Rayleigh Back-scatterBack-scatter

PulsedPulsedLaserLaser


Some Design Trade-offsSome Design Trade-offs


PSF vs Dark Current/QEPSF vs Dark Current/QE

Charge spread Charge spread thickness (z) and thickness (z) and Image Area voltage, (VImage Area voltage, (VIAIA))

Even worse as depletion depth Even worse as depletion depth V VIAIA

Improve PSF byImprove PSF by Thinning device (z)Thinning device (z)

Get rid of undepleted regionGet rid of undepleted region Undesirable as lowers red QEUndesirable as lowers red QE

Increasing Increasing image area clock voltageimage area clock voltage Run non-inverted, but 100 times Run non-inverted, but 100 times

the dark current.the dark current.

Pixel Boundary

0V

VIA

photon

ZVIA

Charge Spread

z2kT/q

VIA

0.5

Depletion depth VImageArea

VImageArea

n buriedchannel

p+

LightInput

Undepleted

p-substrate

Depleted


Package TradeoffsPackage TradeoffsWill use compact Will use compact Peltier cooled packagePeltier cooled package..

Able to fit in small space reserved for AO Able to fit in small space reserved for AO system.system.

Minimal support equipment – no LN2, no Minimal support equipment – no LN2, no cryocoolers, no mechanical moving parts.cryocoolers, no mechanical moving parts.

There are conflicting requirements between:There are conflicting requirements between: CompactnessCompactness solved by Peltier package. solved by Peltier package. Low temperatureLow temperature for low dark current. for low dark current.

Reduce load on cooling by:Reduce load on cooling by: Reducing pin count (thermal conductivity):Reducing pin count (thermal conductivity):

Eliminate all but essential features – Eliminate all but essential features – e.g. no SW.e.g. no SW.

Parallel up as many clocks and biases Parallel up as many clocks and biases as possible; except Vod & Vrd kept as possible; except Vod & Vrd kept separate to reduce cross-talk.separate to reduce cross-talk.

Reducing on-chip power dissipation:Reducing on-chip power dissipation: Make clocks edges as slow as possible.Make clocks edges as slow as possible. Bonus from metal buttressing.Bonus from metal buttressing.

Increase available cooling by:Increase available cooling by: Designing custom Peltier.Designing custom Peltier.


Observatoire de Marseille are building the test controller:Observatoire de Marseille are building the test controller: Loan to e2v for testing.Loan to e2v for testing. Very challenging – go along and talk to Jean-Luc Gach.Very challenging – go along and talk to Jean-Luc Gach.

ESO developing NGC (New General Controller) for deployment on VLT.ESO developing NGC (New General Controller) for deployment on VLT. Test Plan:Test Plan:

E2vE2v Measure normal parameters Measure normal parameters → → noise, gain, cosmetics, dark current, smearing, noise, gain, cosmetics, dark current, smearing,

and CTE.and CTE. IAC (Canary Islands) and ESOIAC (Canary Islands) and ESO

Do full acceptance tests.Do full acceptance tests. Plus measure more exotic parameters Plus measure more exotic parameters → → crosstalk, PRNU, fringing, and PSF.crosstalk, PRNU, fringing, and PSF.

Controller and Test PlanController and Test Plan

Poster: A dedicated controller for Adaptive Optics L3CCD developments.Jean-Luc Gach, Philippe Balard, Olivier Boissin, C. Guillaume.

Poster: NGC Front-end for CCDs and AO applications.Javier Reyes, Mark Downing, Manfred Meyer, Leander Mehrgan, Ralf Conzelmann.

Poster: Software for the New General detector Controller.Claudio Cumani, Andrea Balestra, Joerg Stegmeier.

Oral: NGC Detector Array Controller Based on High Speed Serial.Manfred Meyer, Dietrich Baade, Gert Finger, Leander Mehrgan, Javier Reyes, Joerg Stegmaier.


ChallengesChallenges

The challenges are the number of technology “cutting edge” features:The challenges are the number of technology “cutting edge” features: L3Vision for AO WFSL3Vision for AO WFS –very promising but not yet fully evaluated. –very promising but not yet fully evaluated. Optimized Peltier cooled packageOptimized Peltier cooled package for compactness. for compactness. The technology firsts with L3Vision:The technology firsts with L3Vision:

L3Vision with multiple outputsL3Vision with multiple outputs to reduce clocking rate of individual output nodes to reduce clocking rate of individual output nodes.. Metal buttressingMetal buttressing to reduce frame transfer smear. to reduce frame transfer smear. Deep depletionDeep depletion for better red response. for better red response. Electronic shutterElectronic shutter to enable Rayleigh LG systems. to enable Rayleigh LG systems.

The baseline development is The baseline development is low risklow risk.. e2v, OPTICON, and ESO have formed a e2v, OPTICON, and ESO have formed a very goodvery good partnership. partnership. ConfidentConfident to meet schedule: to meet schedule:

Contract signed last April after many months of constructive negotiations.Contract signed last April after many months of constructive negotiations. Critical Design Review – Aug 2005.Critical Design Review – Aug 2005. Science devices will be available – Q1 2007.Science devices will be available – Q1 2007.


ENDENDMany Thanks for ListeningMany Thanks for Listening

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A Dedicated e2v-L3Vision CCD for Adaptive Optics Applications