Detectors of single photons (…on the road to nano) O. Haderka Regional Center for Advanced Technologies and Materials, Joint Laboratory of Optics, Palacký.

Detectors of single photons (…on the road to nano)

O. Haderka

Regional Center for Advanced Technologies and Materials, Joint Laboratory of Optics, Palacký University, 17. listopadu 50a, 772 07 Olomouc, Czech Republic.

Why to detect single photons?

In classical optics – every photon is valuable (e.g., in astronomy)

In quantum optics/information time-correlated photon counting (TCPC) some tasks benefit from single photons (QKD,

QM) other tasks require single photons (LOQC)

Other applications in particle physics, biomedical research, atmospheric pollution measurements, LIDAR etc.

Photon detection event Coupling Conversion of optical quanta to another medium

(usually electron or electron-hole pair) Amplification to macroscopic level Sampling/Thresholding

amplifier/integrator

sampling/ADC

coupling optics

gain

internal couplingdetector

n mx

losses

ηentryηconv ηcollect γint γext

General characteristics Spectral properties

conversion quantum efficiency ηconv

Timing properties dead time jitter

Noise properties dark count rate d probability of afterpulses

Ability to resolve number of photons excess noise pulse-height diagram single-shot vs. statistics

200 400 600 800 1000 1200 1400 1600 18000

10

20

30

40

50

60

70

80

Qua

ntum

eff

icie

ncy

[%]

Wavelength [nm]

photomultiplier hybrid photodetector Si SPAD InGaAs SPAD

Overview of current technologies

Photomultiplier tubes Avalanche photodiodes Hybrid photodetectors Visible light photon counters Transition-edge sensors Frequency up-conversion Superconducting nanowires Quantum dots & defects Carbon nanotubes (?)

Photomultiplier tubes

the oldest photon-counting detector (1949)

large active areas ( > 10 mm)

amplification excess noise can be lowered using first dynode from suitable material (GaP)

η = 40% @ 500 nm (GaAsP)d ≈ 100 Hz, Δt ≈ 300 ps

η = 2% @ 1550 nm (InP/InGaAs @ 200 K), d ≈ 200 kHz

HamamatsuBurle

Single-photon avalanche photodiode (SPAD)

photodiode reverse biased above breakdown (Geiger mode)

avalanche stopped by quenching circuit

Si: η = 70% @ 650 nm, d ≈ 25 Hz,Δt ≈ 400 ps, τ = 50 ns, high excess noise

back-flashing d can be lowered to 8x10-4 Hz by cooling to 78K shallow-junction: Δt ≈ 40 ps InGaAs/InP: η = 20% @ 1550 nm, d ≈ 10 kHz,

Δt ≈ 400 ps, τ = 10 μs, high excess noise, gating necessary

Perkin-Elmer Micro Photon Devices

idQuantique

Hybrid photodetectors

combination of a photocathode with avalanche photodiode

low excess noise due to single large-amplification step

η = 46% @ 500 nm, d ≈ 1 kHz, Δt ≈ 35 ps

Hamamatsu

Frequency up-conversion conversion

of IR-photons to a region with better detectors

PPLN: 90% conversion very intense pumping needed (cavity or

waveguide) high-noise (background nonlinear processes

emitting at target wavelength due to strong pumping)

η = 46% @ 1550 nm, d ≈ 800 kHz, Δt ≈ 400 ps (thick junction Si SPAD)

coherent up-conversion is feasible

Albota et al., OL 29, 1449 (2004)Langrock et al., OL 30, 1725 (2005)

1550 nm

1064 nm 630 nm

Visible-light photon counters (VLPC)

controlled single-carrier multiplication process @ 6K temperature

avalanche triggered by a hole in As-doped region confined to 20 μm

resolves up to 5 photons ηconv = 88% @ 694 nm

(ηconv = 93% @ near IR), d ≈ 20 kHz, Δt ≈ 250 ps, τ = 100 ns

Kim et al., APL 74, 902 (1999)Takeuchi et al., APL 74, 1063 (1999)

Figure by Y. Yamamoto

Transition-edge sensors superconduction film (W) kept at the

temperature of superconducting transition (100 mK)

photon-absorbtion induced temperature change is detected as a current change

resolves up to 8 photons η = 95% @ 1550 nm,

d ≈ 3 Hz, Δt ≈ 100 ns, τ = 2 μs

can be done at anywavelength between200-1800 nm

Cabrera et al., APL 73, 735 (1998)Rosenberg et al., PRA 71, 061803 (2005)

Lita et al., OE 16, 3032 (2008)

Superconducting nanowires 100 nm wide nanowire in a thin superconducting

film NbN @ 1.5-4K (below superconducting transition) wire biased just below critical current photon detections create resistive hotspots and

trigger voltage pulses η = 1-57% @ 1550 nm,

d ≈ 10 Hz, Δt ≈ 30-60 ps,τ = 10 ns (large area)

deposition of structures for spatial multiplexing possible

improvements likely

Goltsman et al., APL 79, 705 (2001)Marsili et al., NJP 11, 045022 (2009)

Quantum dots or defects trapping of charge in defects heterostructures based on III-V compounds

trapped charge alters conductance in a field-effect transistor (ηconv = 68% @ 805 nm, resolves up to 3 photons)

alters tunneling probabilityin a resonant tunnel diode (ηconv = 12% @ 550 nm, d = 2x10-3 Hz)

4K temperature needed improvements likely

Rowe et al., APL 89, 253505 (2006)Kardynal et al., APL 90, 181114 (2007)

Blakesley et al., PRL 94, 067401 (2005)

Carbon nanotubes (?) multi-wall carbon

nanotubes are grown (CVD) on p-doped silicon substrate

structure behaves like a photodiode with η≈50%

Ambrosio et al., NIMPRA 617, 378 (2010)

Multichannel detectors

[VLPC, HD, nanowires] Fiber-loops Solid state photomultipliers i-CCD cameras EM-CCD cameras

input statevariable ratio

couplerAPD

10m delay loop

connector

2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 01 0 -5

1 0-4

1 0 -3

1 0 -2

1 0 -1

1 00

Pro

ba

bili

ty o

f de

tect

ion

T im e D e la y a fte r sta rt p u lse [n s]

Fiber loops

0 200 400 600 800 1000 1200

10 -5

10 -4

10 -3

10 -2

10 -1

Pro

ba

bili

ty

D elay a fte r trigger [ns ]

Haderka et al., EPJD 28, 149 (2004)Fitch et al., PRA 68, 043814 (2003)

15 m (75 ns)delay loop

30 m (150 ns) delay loop

30 ns electronicsdelay

APD

50/50 splitter

50/50 splitter

50/50 splitter

input state

connector

Multi-pixel photon counter (silicon photomultiplier)

array of APDs in Geiger mode

currently 100 – 1600 pixels

crosstalk due to back-flashes

η = 65% @ 440 nm, d = 6 x 105 Hz, Δt ≈ 200-300 ps

Hamamatsu

iCCD cameras

Photocathode

Microchannel Plate

Fluorescent screen

Electrical connection rings

Fiber Optics

CCD

Microchannel

AndorRoper Scientific

Hamamatsu

η = 25% @ 550 nm, d ~ 104 Hz, Δt ≈ 2 ns

EM-CCD (L3) cameras high η of back-

illuminated CCDs single photon sensitivity CIC noise ‘slow’ shutter η = 97% @ 550 nm

AndorRoper Scientific

Hamamatsu

Figures of merit

For binary detectors:

efficiency factor Qeff

For photon-number resolving detectors:peak-to-valley contrastnumber of resolvable peaks

effective number of channels

n-photon fidelity

tdQeff

tdN 1ENC

Detector comparison chart [Qeff]

400 600 800 1000 1200 1400 1600

2

4

6

8

10

Bur

le 8

850

Ham

amat

su H

1033

0A-7

5

Per

kin-

Elm

er A

QR

16

MP

D

idQ

uant

ique

id20

1

HP

D

Take

sue

et a

l. (2

005)

Take

uchi

et a

l. (1

999)

Lita

et a

l. (2

008)

.

Ros

fjord

et a

l. (2

006)

Row

e et

al.

(200

6)

Had

erka

et a

l. (2

004)

Mič

uda

et a

l. (2

008)

PI-M

AX

512

And

or iS

tar 7

34

And

or iX

on+

888

Ham

amat

su M

PC

C

Jian

g et

al.

(200

7)

log

(Qe

ff)

Wavelength [nm]

photomultiplier SPAD hybrid photodetector up-conversion VLPC TES nanowire quantum dot fiberloop iCCD EMCCD MPPC

Detector comparison chart [ENC]

0 1 2 3 4 5 6

0

20

40

60

80

100

PMT Burle 8850

PMT VIS

PMT IR

Si SPAD PE

Si SPAD MPD

InGaAs SPAD

HPD

up-conversion

VLPC

TES

nanowire

QD

fiberloop

fiberloop

iCCD IR

iCCD VIS

EMCCD

MPPC VIS

MPPC IR

QE

[%]

log(ENC)

photomultiplier SPAD hybrid photodetector up-conversion VLPC TES nanowire quantum dot fiberloop iCCD EMCCD MPPC

n-photon fidelity

0 2 4 6 8 10 12 14 16 18 2010-2

10-1

100

Fid

elity

Fn

Input photon number n

photomultiplier hybrid detector VLPC TES quantum dot fiber loop iCCD MPCC EM-CCD

Olomouc: Application of single-photon detectors to twin photon beams

Characterization of photon-number correlations

Spatial correlations Absolute quantum efficiency

measurement Noise reduction techniques

θi0

θs0

Φs

Φi θi

θsL

τ

w

Λp

Λi

Λs

Type-I spontaneous parametric down-conversion

Generation and measurement of photon twins

Detection with iCCD camerasignal strip idler strip

noise reference

summed image

Photon-number correlations

0 %

0 %

0 %

0 %

0 5 10 15 20 250

5

10

15

20

25

nS

nI

-15 %

-12 %

-9 %

-6 %

-3 %

0 %

3 %

6 %

9 %

12 %

15 %

5060

7080

90100

110120

5060

7080

90100

110120

n S

nI

Haderka et al., PRA 71, 033815 (2005)

Spatial correlations

S I

S I

ideal phasematching

area of correlation

-40 -30 -20 -10 0 10 20 30 40

-40

-30

-20

-10

0

10

20

30

40

S [m rad ]

I [

mra

d]

Spatial correlations:varying the pump beam spectrum

Spatial spectrum of the pump beamTemporal pump-field spectrum

Experimental radial cross-section of the correlation area

Experimental angular cross-section of the correlation area

Spatial correlations:varying the pump beam shape

CONCLUSION

Single photon detection technology makes big leaps

Promising nanotechnologies appear Both intrinsic and multichannel photon-

number resolution improves This all should contribute to present &

future quantum information systems