mauro rajteri, 12/06/2013 panoramica inrim mauro rajteri divisione ottica

Mauro Rajteri, 12/06/2013 Panoramica INRIMMauro Rajteri, 12/06/2013 Panoramica INRIMMauro Rajteri, 12/06/2013 Panoramica INRIM

Mauro Rajteri

Divisione OTTICA

Rivelare i fotoni e la loro statistica con i

Transition-Edge Sensors (TESs)

Panoramica INRIM

Mauro Rajteri, 12/06/2013 Panoramica INRIM 2/46

Photon: also called Light Quantum, minute energy packet of electromagnetic radiation. The concept originated (1905) in Einstein’s explanation of the photoelectric effect (enc. Brittanica)

Photon counting:

Introduction

average count rate intensity of the light beambut

actual count rate fluctuates from measurement to measurement.


3.1

Photon statistics

Coherent light & constant intensity:


Poissonian statistics


Photon source

Single Photon detectors

"Classical" Single photon detector

Photon number resolving (PNR) detector


TES: a superconducting film operated in the temperature region between the normal and the superconducting state

DTc ~ 1 mK high sensitive thermometer

DT DR @ Voltage bias DI

Ibias

t (s)

I

Rbias

<< Rtes

TTc ~ 100 mK

R

Workig Point

Ites





Ibias

t (s)

I

Rbias

<< Rtes

TTc ~ 100 mK

R

Workig Point

Ites

1 ph




T



Tc ~ 100 mK

RI

biast (s)

I

2 phs

Working Point

Rbias

<< Rtes

Ites




10 µm X10 µm

20 µm X 20 µm

Tc =121 mK

∆Tc = 2 mK

Rn = 0.220 Ω

Bilayer – proximity effect Ti=24 nm, Au=54 nm



g= thermal conductance

Thermal bath

Substrate

Superconductor - ph

Superconductor - e

gsub-b

gph-sub

ge-ph

Tb

Tsub

Tph

Te

Pe

Pinc

Ps

)( nsub

ns TTKP

K = constant: material and geometry dependent

n = constant: depends on the dominant thermal coupling mechanism

For T < 1K electron-phonon decoupling n 5

TES: thermal model


Intrinsic Energy Resolution

∆EFWHM is proportional to the operating temperature Tc

Effective TES response time

1

11

nc

ns

thetfT

T

n

24355.2 B

nETkE satcFWHM

c

sat

CTE

TES: theory

etf is lower than th if /n >1


1mm

0,5

mm

back

off

0,5

mm

5 m

m

3 mm0,25

1,5 mm

1,5

mm

0,5 mm

0.8 mm

0,2

5

Silicon

Sili

con

V-g

roov

ew

ith f

iber

arr

ay

Cu bracket

Gaussian beam:w0=4.7/5.6 mm @ l=1.3/1.55 mm

(TES 20 x 20 mm)

2w

0

2w ~

19÷

25 m

m2w

z ~ 125 m

acc ~ 58% @1.55mm ÷ 80% @1.3mm

TES: optical alignment


Optical coupling fiber-TES

Reflection and transmission of superconducting film Antireflection coating or optical cavity

Substrate

2 layers

SubstrateSubstrate

2 layers

Substrate

R(1550)=0.018%

a-SiH (high reflection index)

a-Si3N4:Hy (low reflection index)

TES: optical losses


Optical fiber

DITES

Electronics & data

aquisition

INRIM: TES module SQUID current

sensors (PTB)

Laser

Attenuator

TES: photon counting


0 10 20 30 40 50 600

200

400

600

800

1000

1200

1400

1600

1800

2000

amplitude [mV]

occurr

ences

histogram noisy

fit

543

2

1

Noisy: ΔE = 0.46 eV

Wiener: ΔE = 0.22 eV

0 10 20 30 40 50 600

500

1000

1500

2000

2500

3000

amplitude [mV]

occu

rren

ces

histogram Wiener

fit

(a)

(b)

D. Alberto, et al, Optical Transition-Edge Sensors Single Photon Pulse Analysis, IEEE Trans. Appl. Supercond., 21 , 285 – 288 (2011)

TES: pulse analysis

Wiener filter: 2x improvement on E


L. Lolli, et al. J. Low Temp. Phys., vol. 167, pp. 803-808, 2012.

20X20 μm2

=1570 nm

phs



wp

wi

ws

PARAMETRIC CRYSTAL

COUNTER

COINC COUNTER

Absolute Quantum Efficiency

COUNTER

N

Detector to be Calibrated

“Herald” Detector

N1=1N N2=2N NC=12N

1=NC/ N2

NC

N1

N2

Klyshko

TES: QE absolute calibration

Drawback: Klyshko's technique is not able to exploit the PNR ability of the detector

Proposal and demonstration of an absolute technique for measuring quantum efficiency, based on an heralded single photon source, but exploiting the PNR ability of the detector

A. Avella et al OPTICS EXPRESS 2011 19 p. 23249-23257


Probability of observing i photons per heralding count

in the presence of the heralded photonProbability of observing i photons per heralding

count in the absence of the heralded photon (i.e. of observing i “accidental” counts)

“Total” Quantum Efficiency of the PNR detector optical and coupling losses detector proper Quantum Efficiency

Probability of having a True Heralding Count (not due to stray-

light or dark counts)

The probability of observing 0 photons per heralding count :

Non detection & No accidental

)0()1()0()1()0( AAH PPP

)(iPH

)(iPA

False her.& No accidental



From each a value of “Total” Quantum Efficiencycan be estimated Consistency Test

The probability of observing i photons per heralding count

From the probability of 0

From the probability of i

Hp of the Klyshko’s Technique:multiphoton PDC events negligible

Hp of the Klyshko’s Technique:multiphoton PDC events negligible

)()1()]1()()1[()( iPiPiPiP AAAH

)(iPH

)0(

)0()0(0

A

HA

P

PP

)]()1([

)()(

iPiP

iPiP

AA

AHi



TES detection system

HWP

IF1

IF2

NLC

ab

PDC single photon source

DET1

Pump source



Heralded Accidental

prob. of true heralding counts

total quantum efficiency

@ 807 nm

DET1

PUMP


6 Repeated measurementseach 5 hr. long >5 106 counts


“n”

POVM provides the description of the measurement process

Prob. of output “n”

TES: POVM tomography


“n”





“n”



: Prob. of having output “n” with m photons as input



Simplest Solution:

Fock state source



Simplest Solution:

Fock state source

Affordable Solution: Coherent source[Lundeen et al., Nat. Phys 5, 27 (2009)]



Coherent source

Pulsed laser source

Experiment with a TES

1570 nm



Coherent source

Pulsed laser source




Coherent source

Linear detection model

=5.1%

G. Brida et al New Journal of Physics 14 (2012) 085001



ADR cold fingerAlignment:

Joint Projects for the exchange of researchers within the Executive Programme Italy-Japan 2010-2012

Fast TES


Fast TES


=1535 nm QE 50 %

TiAu TES Tc=301 mK

73 phs

@ 500 kHz means 3.65x106 photons/s (473 fW)

Fast TES


Fast TESs review


TES: High energy resolution

45nm Au+45nm Ti10 mm x 10 mm

Tc=106 mKCe=0.35fJ/K

Rn=0.45

D

ITTRITR cn

tanh12

),(

),(

)(),(2

ITRRRIRIIL

TTkITIRTC

spsbias

ns

ne

23

pW/K441

ncnkTG


teff = 3.8 ms

DE = (0.113 ± 0.001) eV

(Submitted to APL)

TES: High energy resolution

12

12ln22xx

EE


Impedance


Conclusions

TES Photon number resolving detectors

Wavelength range: UV-IR

Quantum efficiency:50%90%

Dark counts: background limited

Count rate: 1 MHz

Working temperature: < 1K


Chi fa cosa

Fabbricazione: C. Portesi, E. Monticone

Caratterizzazione : E. Taralli, L.Lolli , E. Monticone, M. Rajteri(criogenica, elettrica e ottica)

E. Taralli, L. Callegaro (impedenza)

Sviluppo

Taratura Applicazioni

Ottica quantistica: A. Avella,G. Brida, L. Ciavarella, I. Degiovanni, M. Genovese, M. Gramegna, M.G. Mingolla,F. Piacentini, M.L. Rastello, P. Traina

Collaborazioni J. Beyer, D. Fukuda, T. Numata, M.G.A. Paris, M. White,G. Cantatore, G. Ventura


Finanziamenti

Progetto premiale P5 (2012-2013)Oltre I limiti classici della misura

NEW08 MetNEMS (2012-2015)Metrology with/for NEMS

Quantum Candela (2008-2011)

E45 (2006-2010)Rivelatori superconduttivi a transizione di fase per conteggio di singoli fotoni

2001-2004 -Fotorivelatori superconduttivi ad elettroni caldi per il VIS-IR-Realizzazione di STJ come rivelatori in regime di conteggio di fotoni per applicazioni astrofisiche


Grazie per l’attenzione!

mauro rajteri, 12/06/2013 panoramica inrim mauro rajteri divisione ottica

Documents

pnr detector slide

brittanica photon

t s i r bias

light beam

light quantum

voltage bias

superconducting state

average count rate intensity