Quantum limits of deep space optical communication Konrad - - PowerPoint PPT Presentation

Quantum limits

• f deep space optical

communication

Konrad Banaszek, Ludwig Kunz, Marcin Jarzyna, Michał Jachura, Wojciech Zwoliński

Centre for Quantum Optical Technologies, University of Warsaw, Poland k.banaszek@cent.uw.edu.pl 2018 Munich Workshop

• n Information Theory of Optical Fiber

6 December 2018

Satellite optical communication

• H. Hemmati, A. Biswas, and I. Djordjevic,

Deep-Space Optical Communications: Future Perspectives and Applications,

• Proc. IEEE 99, 2020 (2011)

Optical vs radio frequency communication Benefits:

• Access to higher

bandwidths

• Lower diffraction losses
• Reduced regulatory

requirements Challenges:

• Robustness against

atmospheric conditions

• Wall-plug efficiency
• f onboard transceivers
• Pointing and tracking
• Antenna surface quality

Deep-space rf communication links

• D. Boroson, On achieving high performance optical communications

from very deep space, Proc. SPIE 10524, 105240B (2018)

Deep-space optical communication

• D. Powell, Lasers boost space communications, Nature 499, 266 (2013)

Planck’s constant

Signal strength

Average detected number of photons per slot: frequency transmitter power time carrier frequency B bandwidth modulation rate channel transmission and detection efficiency slot duration

System characteristics

• B. Moision and W. Farr, IPN Prog. Rep. 42-199, 1-10 (2014)

Channel transmission: Signal central wavelength

Phase-insensitive Gaussian channel

Linear attenuation Excess noise

Homodyne capacity per slot Heterodyne capacity per slot channel excess noise shot-noise limited detection

Total:

Shannon-Hartley theorem

Quantum Shannon theory

Input ensemble Holevo quantity : for any measurement on the output ensemble Channel Output ensemble For a phase-insensitive Gaussian channel under average power constraint: where

• V. Giovannetti, R. García-Patrón, N. J. Cerf, A. S. Holevo, Nature Photon. 8, 796 (2014)

where is the von Neumann entropy.

2 4 6 8 10 1 2 3 4 5

Pure loss channel

Average detected photon number Capacity [bits/slot]

heterodyne homodyne

Photon information efficiency

10-4 0.001 0.010 0.100 2 4 6 8 10 12 14

Average detected photon number Photon information efficiency PIE

Information rate [bits/s]:

?

heterodyne homodyne

PPM – Pulse Position Modulation

erasure pulse optical energy

… … …

Symbols: Geiger-type direct detection Photocount probability (symbol recovery):

PPM photon information efficiency

10-4 0.001 0.010 0.100 2 4 6 8 10 12 14

Average detected photon number Photon information efficiency PIE

heterodyne homodyne 16 128 256 512 1024 2048 32 64 PPM order

PPM PIE asymptotics

Lambert function for Optimal PPM order

Average detected photon number Photon information efficiency

• M. Jarzyna, P. Kuszaj, K. Banaszek, Opt. Express 23, 3170 (2015)

10-4 0.001 0.010 0.100 2 4 6 8 10 12 14

Photocount probability: Approximate analytical expression:

numerical ( )

• approx. analytical

10-4 0.001 0.010 0.100 2 4 6 8 10 12 14

Photon information efficiency

Superadditivity of accessible information

• S. Guha, Phys. Rev. Lett. 106, 240502 (2011)

+ + + + + + + + + – + – + – + – + + – – + + – – + – – + + – – + + + + + – – – – + – + – – + – + + + – – – – + + + – – + – + + –

BPSK:

− − − − + + +

homodyne Holevo quantity χ for BPSK format

Holevo quantity assumes:

• preparation of codewords
• collective detection of

multiple symbols Hadamard codewords

+ + + –

Linear optical circuit (structured receiver)

…

Scalable structured receiver

• K. Banaszek and M. Jachura, Proc. IEEE ICSOS 2017, pp. 34-37

1 1 1 1

1 1 1 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1

Pulse position: τ

T T T T

Realization

1 1 1 1

1 1 1 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1

Pulse position: τ polarization switching

• K. Banaszek and M. Jachura, Proc. IEEE ICSOS 2017, pp. 34-37

Phase-polarization patterns

symbol symbol guard-time guard-time

Polarization-dependent delay + rotation by 45o PPM encoding achieved by shifting the entire pattern in time

• K. Banaszek and M. Jachura, Proc. IEEE ICSOS 2017, pp. 34-37

Atmospheric turbulence

• J. Jin et al., Demonstration of analyzers

for multimode photonic time-bin qubits,

• Phys. Rev. A 97, 043847 (2018)

wavefront distorted signal

Multimode DPSK receiver

• Z. Sodnik and M. Sans, Extending

EDRS to Laser Communication from Space to Ground,

• Proc. ICSOS 2012, 13-2

Noisy channel asymptotics

10-4 0.001 0.010 0.100 2 4 6 8 10 12 14

Background noise power

heterodyne homodyne Holevo Average detected photon number Photon information efficiency

Optimized PPM with background noise

complete decoding

• W. Zwoliński, M. Jarzyna, and K. Banaszek, Opt. Express 26, 25827 (2018)

Background noise

simple decoding

• multimode background noise yielding Poissonian count statistics
• Geiger-type direct detection
• unconstrained peak-to-average power ratio (PPM order)

Range dependence

• W. Zwoliński, M. Jarzyna, and K. Banaszek, Opt. Express 26, 25827 (2018)

complete decoding simple decoding

High-order modulation formats

• K. Banaszek, M. Jachura, W. Wasilewski, Utilizing time-bandwidth space for efficient deep-space

communication, Proc. International Conference on Space Optics 2018, paper P22

pulse position modulation frequency shift keying BPSK Hadamard codewords

Thank you!