6-ccpr metrology for quantum communication sept2016 - BIPM€¦ · Source Spectrum Wavelength •...
Transcript of 6-ccpr metrology for quantum communication sept2016 - BIPM€¦ · Source Spectrum Wavelength •...
METROLOGY
FOR
QUANTUM COMMUNICATION
Giorgio Brida
Workshop on Fiber Optics Metrology needs19 September 2016 Paris, BIPM
Metrology for Industrial
Quantum Communications
Sept. 2011 – Aug. 2014
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Project Partners
Metrology for Industrial Quantum Communicationshttp://www.miqc.org/
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Optical metrology for
quantum-enhanced secure telecommunication
July 2015 – June 2018
This project follows on from EMRP project MIQC
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Optical metrology for
quantum-enhanced secure telecommunicationhttp://www.miqc.org/
Project Partners
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
• Objective : to develop a pan-European
measurement infrastructure to develop standards
and characterisation facilities for commercial
Quantum Key Distribution (QKD) devices.
• QKD devices require independent physical
characterisation in order to convince end-users
that the technology is working within specification
• Focus on faint-pulse (weak coherent pulse) QKD
over fibre at 1550 nm
Metrology for Industrial Quantum Communicationshttp://www.miqc.org/
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
These projects work closely with the ETSI
Industry Specification Group on QKD
ETSI ISG-QKD
Standardisation
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Photon emitters Traceable characterisation of commercial QKD sources:
• Attenuated laser pulses
Photon receiversTraceable calibration of commercial QKD receivers:
• Gated photon counting detectors
Quantum channel (optical fibre) and RNG • Traceable characterisation of single mode optical fibre
• Characterisation of propagation of photon state in single mode fibre
• Open system true physical quantum random number generator (QRNG)
• QRNG physically characterised and tested under different operating
conditions
Focus on faint-pulse (weak coherent pulse) QKD over fibre at 1550 nm
24-27 June 2014
Metrology for Industrial Quantum Communicationshttp://www.miqc.org/
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Photon emitters Traceable characterisation of commercial QKD sources:
• Attenuated laser pulses
Photon receiversTraceable calibration of commercial QKD receivers:
• Gated photon counting detectors
Key Measurement Outputs of MIQC
Quantum channel (optical fibre) and RNG • Traceable characterisation of single mode optical fibre
• Characterisation of propagation of photon state in single mode fibre
• Open system true physical quantum random number generator (QRNG)
• QRNG physically characterised and tested under different operating
conditions
24-27 June 2014
Focus on faint-pulse (weak coherent pulse) QKD over fibre at 1550 nm
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Detectors’ parameters considered [1/2]Parameter Symbol Units Definition Measurement approach
Photon detection
probability
h probability/
gate
The probability that a photon incident at
the optical input will be detected within a
detection gate.
Via a calibrated laser light
source and a calibrated filter
Dark count
probability
Pdark (probability
/gate)
The probability that a detector registers a
detection event per gate, despite the
absence of optical illumination.
As above (1)
Afterpulse probability Pafterpulse (probability
/gate)
The probability that a detector registers a
false detection event in the absence of
illumination, conditional on a true photon
detection event in the preceding detection
gate.
As above (1)
Dead time Tdead ns/µs The smallest time duration after which the
detection efficiency is independent of
previous photon detection history.
Via a train of two optical
pulses with tuneable temporal
separation
Recovery Time Trec ns/µs The time duration after a photon detection
event for the detection efficiency to return
to 99% of its steady-state value. This is only
important if the detector is passively
quenched
As above (4)
Receiver’s Detectors
24-27 June 2014Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Detectors’ parameters considered [2/2]Parameter Symbol Units Definition Measurement approach
Maximum count rate Cmax MHz/GHz The maximum rate of photon detection
events under strong illumination condition
in the single/few photon/gate regime.
This will be determined by the
photon detection efficiency,
the dead time, and dark
counts
Timing jitter Tjitter ps/ns The uncertainty in determining the arrival
time of a photon at the optical input.
Measure the FWHM in the
distribution of detection times
Maximum clock
frequency
Fmax MHz/GHz The maximum clock frequency at or below
which a detector can be operated in a QKD
system without giving rise to an intolerable
bit error rate.
Spectral Responsivity Rs unitless The photon detection efficiency as a
function of wavelength of the incident
photons.
Via a calibrated laser light
source with known
wavelength (wavemeter) and
a calibrated filter
Receiver’s Detectors
24-27 June 2014Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Detectors’ parameters considered [1/2] (again!)
Parameter Symbol Units Definition Measurement approach
Photon detection
probability
h probability/
gate
The probability that a photon incident at
the optical input will be detected within a
detection gate.
Via a calibrated laser light
source and a calibrated filter
Dark count
probability
Pdark (probability
/gate)
The probability that a detector registers a
detection event per gate, despite the
absence of optical illumination.
As above (1)
Afterpulse probability Pafterpulse (probability
/gate)
The probability that a detector registers a
false detection event in the absence of
illumination, conditional on a true photon
detection event in the preceding detection
gate.
As above (1)
Dead time Tdead ns/µs The smallest time duration after which the
detection efficiency is independent of
previous photon detection history.
Via a train of two optical
pulses with tuneable temporal
separation
Recovery Time Trec ns/µs The time duration after a photon detection
event for the detection efficiency to return
to 99% of its steady-state value. This is only
important if the detector is passively
quenched
As above (4)
24-27 June 2014Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Optical power traceability chain (SI)
0.005 % uncertainty
visible wavelengths,0.5 mW,collimated, free-space laser radiation
1 % uncertainty (k = 2)
1550 nm,100 pW,output from optical fibre
Primary standardCryogenic radiometry
NMI reference detectors
Low power reference detector
24-27 June 2014Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Φ = N (hc/λ)
N
Air coupling, 2mm beam
Uncertainty ≈ 100 ppm
Air/fibre coupling, ≈ 10 μm beam
Uncertainty ??
100 dB
SPAD
TES
SSPD
TRACEABILITY
- Stability
- Beam shape
- Background
- … !!!
532 nm -2,74 dB
633 nm -1,99 dB
850 nm -0,71 dB
1550 nm +1,90 dB
Optical power traceability chain (SI)
200 µW ECSR
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
PTB CryogenicRadiometer
PTB CryogenicRadiometer
PTB referenceInGaAs detectorPTB reference
InGaAs detector
Metrology Light Source –
dedicatedelectron storage
of PTB
Metrology Light Source –
dedicatedelectron storage
of PTB
SuperconductingSingle Photon
Detector
SuperconductingSingle Photon
Detector
Novel reference for calibrating single-photon
detectors based on synchrotron radiation
Exploitation of strict proportionality of ring current and emitted radiation
Number of stored electrons changes spectral radiant power over 11orders of magnitude without changes to the emitted spectrum
910≈−eN 310≈−e
N
24-27 June 2014
QESSPD* = count rateSSPD number of stored electrons ( I low )
photon rateTrap number of stored electrons ( Ihigh )
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Photon emitters Traceable characterisation of commercial QKD sources:
• Attenuated laser pulses
Photon receiversTraceable calibration of commercial QKD receivers:
• Gated photon counting detectors
Key Measurement Outputs of MIQC
Quantum channel (optical fibre) and RNG • Traceable characterisation of single mode optical fibre
• Characterisation of propagation of photon state in single mode fibre
• Open system true physical quantum random number generator (QRNG)
• QRNG physically characterised and tested under different operating
conditions
24-27 June 2014Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Photon emitters Traceable characterisation of commercial QKD sources:
• Attenuated laser pulses
Photon receiversTraceable calibration of commercial QKD receivers:
• Gated photon counting detectors
Key Measurement Outputs of MIQC
Quantum channel (optical fibre) and RNG • Traceable characterisation of single mode optical fibre
• Characterisation of propagation of photon state in single mode fibre
• Open system true physical quantum random number generator (QRNG)
• QRNG physically characterised and tested under different operating
conditions
Focus on faint-pulse (weak coherent pulse) QKD over fibre at 1550 nm
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Source parameters considered [1/2]
Parameter Symbol Units Definition Measurement approach
Frequency (Rep.
Rate)
F Hz The frequency set by the
pulse generator
Measure via standard traceable frequency calibration
techniques
Mean photon
number
µ Photons
/pulse
Average number of
photons per pulse emitted
by Alice
a) calibrated detector and commercial attenuator
b) calibrated detector and traceable attenuator based
on InGaAs photodiodes
c) reconstruction of probability distribution
d) Photon number resolving detector based on
commercial single photon detector in tree
configuration
Mean photon
number variation
σµ As above
Source timing jitter JS ps or ns The uncertainty in the
emission time of a photon
at the optical output.
Measure FWHM of distribution of photon emission times
with respect to pulse generator signal
Emitter’s Sources
24-27 June 2014Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Source parameters considered [2/2]
Parameter Symbol Units Definition Measurement approach
Source wavelength λ nm Wavelength of photons
that are emitted.
Wavemeter
Spectral line width δ GHz Bandwidth of the emitted
photons.
Beat note measurement or Fabry-Perot interferometer.
Spectral
indistinguishability
sind Unitless The extent to which the
encoded states can be
distinguished through
spectral measurement.
Fabry-Perot interferometer: compare spectra of different
encoding states
Temporal
indistinguishability
tind Unitless The extent to which the
encoded states can be
distinguished through
temporal measurement.
The probability distribution with respect to time for laser
output pulses is measured. tind is calculated according to
reference [12].
Polarisation state Polarisation reconstruction
Emitter’s Sources
24-27 June 2014Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Source parameters considered [1/2] (again!)
Parameter Symbol Units Definition Measurement approach
Frequency (Rep.
Rate)
F Hz The frequency set by the
pulse generator
Measure via standard traceable frequency calibration
techniques
Mean photon
number
µ Photons
/pulse
Average number of
photons per pulse emitted
by Alice
a) calibrated detector and commercial attenuator
b) calibrated detector and traceable attenuator based
on InGaAs photodiodes
c) reconstruction of probability distribution
d) Photon number resolving detector based on
commercial single photon detector in tree
configuration
Mean photon
number variation
σµ As above
Source timing jitter JS ps or ns The uncertainty in the
emission time of a photon
at the optical output.
Measure FWHM of distribution of photon emission times
with respect to pulse generator signal
24-27 June 204Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Source photon number statistics
Reconstruction of probability distribution
Photon number distribution
For on/off detectors like SPAD with quantum efficiency �, the probability of no-
clicks is:
“ON/OFF” Tomography
-Truncating the p.d. to a certain �
-Changing the value of the quantum efficiency��
Poissonian
Reconstructed
24-27 June 2014Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Source photon number statistics
1310 nm laser
Transition Edge Sensor i.e. µcalorimeter working at
superconductive phase transition
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Source photon number statistics
d) PNR detector based on tree configuration
Detector Tree:
4 click/no-click
detectors
BS
BS
BS
( )( )
(2) (3) (4) ( ), , 1
nn
P ng g g g
P=
• By measuring higher-order g(n), it is possible to deconvolve
the underlying number and kind (poissonian, pseudo-
termal or single-photon) of occupied modes of a light field.
Deconvolving the p.d. of incoming photons
Goldschmidt et al., PRA
88, 013822 (2013)
24-27 June 2014
• Novel (entanglemet-assisted) quantum
characterisation technique for PNR
detector Brida et al., PRL 108, 253601 (2012)
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Parameter Symbol Units Definition Measurement approach
Source wavelength λ nm Wavelength of photons
that are emitted.
Wavemeter
Spectral line width δ GHz Bandwidth of the emitted
photons.
Beat note measurement or Fabry-Perot interferometer.
Spectral
indistinguishability
sind Unitless The extent to which the
encoded states can be
distinguished through
spectral measurement.
Fabry-Perot interferometer: compare spectra of
different encoding states
Temporal
indistinguishability
tind Unitless The extent to which the
encoded states can be
distinguished through
temporal measurement.
The probability distribution with respect to time for
laser output pulses is measured.
Polarisation state Polarisation reconstruction
Source parameters considered [2/2] (again!)
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Source Spectrum
Wavelength
• Optical pulses of duration < 100 ps
• Spectral width: ∆νsource ~ 12 GHz (@1550 nm)
• Target uncertainty in λsource of δλsource < 0.01 nm (1.2 GHz @1550 nm)
Wavemeter measurement
• Needs to be high flux (before attenuation)
• standard interferometer design not necessarily good for pulsed laser
• can use alternative design (eg High Finesse) suitable for pulsed sources
24-27 June 2014Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Source Spectrum
Tunable single-photon spectrometer
• Operating range 1270 → 1630 nm
• FSR = 119 GHz, ∆νcavity = 600 MHz
• Low drift rate & single-photon sensitivity
• Tune to resonance and scan across QKD source spectrum
• Can be used to analyse different source encoding spectra
• Technically challenging to improve spectral resolution
24-27 June 2014Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Parameter Symbol Units Definition Measurement approach
Source wavelength λ nm Wavelength of photons
that are emitted.
Wavemeter
Spectral line width δ GHz Bandwidth of the emitted
photons.
Beat note measurement or Fabry-Perot interferometer.
Spectral
indistinguishability
sind Unitless The extent to which the
encoded states can be
distinguished through
spectral measurement.
Fabry-Perot interferometer: compare spectra of
different encoding states
Temporal
indistinguishability
tind Unitless The extent to which the
encoded states can be
distinguished through
temporal measurement.
The probability distribution with respect to time for
laser output pulses is measured.
Polarisation state Polarisation reconstruction
Source parameters considered [2/2] (again!)
24-27 June 2014Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Noiseless Heralded SPS
HBTHBT
∆tswitch
24-27 June 2014
g(2) =
∆tswitch = 2ns
Brida et al., APL 101, 221112 (2012)
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Photon emitters Traceable characterisation of commercial QKD sources:
• Attenuated laser pulses
Photon receiversTraceable calibration of commercial QKD receivers:
• Gated photon counting detectors
Key Measurement Outputs of MIQC
Quantum channel (optical fibre) and RNG • Traceable characterisation of single mode optical fibre
• Characterisation of propagation of photon state in single mode fibre
• Open system true physical quantum random number generator (QRNG)
• QRNG physically characterised and tested under different operating
conditions
24-27 June 2014Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Photon emitters Traceable characterisation of commercial QKD sources:
• Attenuated laser pulses
Photon receiversTraceable calibration of commercial QKD receivers:
• Gated photon counting detectors
Key Measurement Outputs of MIQC
Quantum channel (optical fibre) and RNG • Traceable characterisation of single mode optical fibre
• Characterisation of propagation of photon state in single mode fibre
• Open system true physical quantum random number generator (QRNG)
• QRNG physically characterised and tested under different operating
conditions
Phase encoded, attenuated laser pulse QKD over fibre at 1550 nm
24-27 June 2014Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Polarization state reconstruction
- CW or quasi-CW source before attenuation: conventional polarimeter
- Pulsed source (challenging)
- Attenuated Source (single-photon light level): quantum state tomography
- Issue: polarization stability
Evaluation of the parameters: {S1 , S2 , S3}
3 projective measurements: :
24-27 June 2014Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
MIQC 2http://www.miqc2.org/
MIQC 2WP1: Counter-measures and novel optical
components for commercial fibre-based QKD
The aim of this work package is to characterise and validate counter-measures to side-channel
and Trojan-horse attacks in order to ensure the security of fibre-based QKD systems. This
activity is carried on in strict collaboration with the ETSI Industry Specification Group on QKD.
• Identify vulnerabilities of passive and active
components
• Develop and verify counter-measures
• Develop security models
• Characterise a new, high-speed, type of SPAD
• Intercomparison of fibre-coupled DE and g2
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
MIQC 2WP2: Metrology for commercial components for
free-space QKD
The aim of this work package is to establish measurement and characterisation facilities for
components of free-space QKD devices. Within the scope of this project, we define the spectral
range as that where silicon-based detectors are applicable, i.e. between 400 nm and 950 nm.
• Develop characterisation facilities facilities for
free-space QKD components
• develop tests for Quantum Random
Generators
• absolute reference detector for in-situ
calibration of SPADs
• Intercomparison of free-space DE and g2Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
MIQC 2WP3: Metrology for next generation (entanglement-
based) QKD
The aim of this work package is to foster the development of a measurement infrastructure for
entanglement-based (next-generation) QKD systems, such as device-independent,
measurement device-independent and reference-frame independent QKD.
• Develop metrics and measurement apparatus
for entanglement and quantumness
quantification
• Apply to key properties of measurement-
device-indipendent QKD
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
MIQC 2
Joint Virtual European Metrology Centre for Quantum Photonics
… a general objective of the project is investigating thepossibility of establishing the “Joint Virtual EuropeanMetrology Centre for Quantum Photonics” between thepartners. A strategic analysis for the creation of this Centre willbe carried out, which will include consultation with stakeholdersand CCPR, and report on the need and proposed terms-of-reference for this Joint Centre.
IMPACT
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Achievements
�SPAD back-flash emission done� pilot comparison of SPAD d.e. started
� entanglement meas. for QKD applications on going
� Fiber link 640 km QKD INRIM-LENS (Florence) on going
MIQC 2
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Photon-counting
optical time-domain reflectometry
at 1550 nm
Back-flash from SPAD
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
NEWRAD 2014, 24-27 June, Espoo
Pulse
generator
Pulsed
laser
Optical
attenuator
Correlator
Free running
SPADID300
ID220
Fibre optic
device
circulator
sync
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
0 5 10 15 20 25 30
10
100
1000
104
105
106
107
Co
un
ts
t/µs
Round & trip
SPAD dead time
1 km fibre
Rate 10 kHz
α = 33 dB
T = 1 h
bin = 1,024 ns
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
NEWRAD 2014, 24-27 June, Espoo
Pulse
generator
Pulsed
laser
Optical
attenuator
Correlator
Free running
SPADID300
ID220
SPAD
circulator
sync
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
0 50 100 150 200
10
100
1000
Co
un
ts
t/ns t/ns
SPAD - OFF
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Co
un
ts
t/ns
0 50 100 150 2001
10
100
1000
t/ns
SPAD - ON
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Co
un
ts
t/ns 0 50 100 150 200
1
10
100
1000
t/ns
SPAD - OFF
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
Co
un
ts
t/ns
0 50 100 150 200
10
100
1000
104
t/ns
SPAD - ON
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
NEWRAD 2014, 24-27 June, Espoo
SPAD - ON
Increasing the excess
bias voltage
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
I-QB POINT-TO-POINT LINK
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
First phase: december 2015
INRIM
SANTHIA’Link: INRIM –SANTHIA’
92 Km, -27 dB losses
• Clavis 3 system (Emitter & Receiver)
• 2xID230 external detectors : SKR >10 bps @ 30 dB
• 2 PC or Laptop to control Clavis 3 units
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
ITU29 1554.29nm
ITU32 1551.72nmFC/APC
ITU30 1553.33nm
FC/APC
Alice Bob
Clavis3
Quantum channel
(dark fiber)
FC/PCSMA
FC/APC
SMA
FC/PC
FC/APC
SMA
SMA
Ethernet (LAN)
ITU30
ITU29
WDM WDMClavis3
AMPLIF.
+ FILTER
ITU29
ITU30
ADD
DROP
ADD
DROP
Ethernet (LAN)
PC/Laptop
PC/Laptop
ID230
ID230
Classical channel
19” rack 19” rack
2x LC/PC 2x LC/PC
Ethernet (WAN)
Ethernet (WAN)
Power consumption of
the Clavis3: <250W
(220AC)
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM
I-QB: 1st Meeting: October 14th, 2015
Second phase: december 2016-2017
• Optimisation of first phase link
• SKR >10 bps @ 30 dB
• Link: INRIM – UNIFI-LENS
• 642 km, -171 dB losses
• Sub-link losses: -25 to -34 dB
• 7 TN and 6 sub-links
• Detectors at 4 nodes
• TNs architecture to transmit securely
the secret key over long distances
Workshop on Fiber Optics Metrology needs - 19 September 2016 Paris, BIPM