Transcript QUANTEYE - Lund Observatory

Quantum Optics @ OWL
D. Dravins 1, C. Barbieri 2
V. DaDeppo 3, D. Faria 1, S.Fornasier 2
R. A. E. Fosbury 4, L. Lindegren 1
G. Naletto 3, R.Nilsson 1, T. Occhipinti 3
F. Tamburini 2, H. Uthas 1, L. Zampieri 5
(1) Lund Observatory
(2) Dept. of Astronomy, University of Padova
(3) Dept. of Information Engineering, Univ. of Padova
(4) ST-ECF, ESO Garching
(5) Astronomical Observatory of Padova
• Explore parameter domains
beyond those of today’s
astronomy
• Observe what cannot be seen
by imaging, photometry,
spectroscopy, polarimetry, nor
interferometry
• Open up quantum optics as
another information channel
from the Universe!
LASER ---
COHERENT ---
CERENKOV --OBSERVER
Information content of light. I
D.Dravins, ESO Messenger 78, 9 (1994)
Intensity interferometry
Narrabri stellar intensity interferomer circa 1970 (R.Hanbury Brown, R.Q.Twiss et al., University of Sydney)
• PHOTONS ARE COMPLEX ! !
• Photon streams carry
information in the temporal
ordering of photon arrival times
• Individual photons carry
orbital angular momentum,
can have hundreds of states
Quantum effects in cosmic light
Examples of
astrophysical
lasers
J. Talbot
Laser Action in Recombining Plasmas
M.Sc. thesis, University of Ottawa (1995)
Quantum effects in cosmic light
Hydrogen recombination
lasers & masers
in MWC 349 A
Circumstellar disk surrounding the hot star MWC 349. Maser emissions are thought to
occur in outer regions while lasers are operating nearer to the central star.
V. Strelnitski; M.R. Haas; H.A. Smith; E.F. Erickson; S.W. Colgan; D.J. Hollenbach
Far-Infrared Hydrogen Lasers in the Peculiar Star MWC 349A
Science 272, 1459 (1996)
Quantum Optics & Cosmology
The First Masers
in the Universe…
The black inner region
denotes the evolution
of the universe before
decoupling.
Arrows indicate maser
emission from the epoch
of recombination and
reionization.
M. Spaans & C.A. Norman
Hydrogen Recombination Line Masers at the Epochs of Recombination and Reionization
ApJ 488, 27 (1997)
Synergy OWL ― SKA
SKA: Hydrogen
recombination lasers
in the very early
Universe
OWL: Hydrogen
recombination lasers in the
nearby Universe
Quantum effects in cosmic light
Emission-line lasers
in Eta Carinae
Eta Carinae
Mid-IR (18 μm)
images from 4-m
Blanco telescope at
Cerro Tololo.
Field  25 arcsec
Model of a compact gas condensation near η Car with its Strömgren boundary
between photoionized (H II) and neutral (H I) regions
S. Johansson & V. S. Letokhov
Laser Action in a Gas Condensation in the Vicinity of a Hot Star
JETP Lett. 75, 495 (2002) = Pis’ma Zh.Eksp.Teor.Fiz. 75, 591 (2002)
S. Johansson & V.S. Letokhov
Astrophysical lasers operating in optical Fe II lines in stellar ejecta of Eta Carinae
A&A 428, 497 (2004)
Quantum effects in cosmic light
Emission from
neutron stars,
pulsars & magnetars
T.H. Hankins, J.S. Kern, J.C. Weatherall, J.A. Eilek
Nanosecond radio bursts from strong plasma turbulence in the Crab pulsar
Nature 422, 141 (2003)
Longitudes of giant
pulses compared
to the average
profile.
Main pulse (top);
Interpulse (bottom)
V.A. Soglasnov et al.
Giant Pulses from PSR B1937+21 with Widths ≤ 15 Nanoseconds and Tb ≥ 5×1039 K, the
Highest Brightness Temperature Observed in the Universe, ApJ 616, 439 (2004)
Coherent emission from magnetars
o Pulsar magnetospheres emit in radio;
higher plasma density shifts magnetar
emission to visual & IR (= optical emission in
anomalous X-ray pulsars?).
o Photon arrival statistics (high brightness
temperature bursts; episodic sparking
events?). Timescales down to nanoseconds
suggested (Eichler et al. 2002).
Quantum Optics @ OWL
Detecting
laser effects in
astronomical radiation
Information content of light. II
D.Dravins, ESO Messenger 78, 9 (1994)
Photon correlation spectroscopy
o To resolve narrow optical laser emission
(Δν  10 MHz) requires spectral
resolution λ/Δλ  100,000,000
o Achievable by photon-correlation
(“self-beating”) spectroscopy !
Resolved at delay time Δt  100 ns
o Method assumes Gaussian (thermal)
photon statistics
Photon correlation spectroscopy
LENGTH,
TIME &
FREQUENCY
FOR
TWO-MODE
SPECTRUM
E.R.Pike, in R.A.Smith, ed. Very High Resolution Spectroscopy, p.51 (1976)
Photon correlation spectroscopy
LENGTH & TIME FOR SPECTROMETERS OF DIFFERENT RESOLVING POWER
E.R.Pike, in R.A.Smith, ed. Very High Resolution Spectroscopy, p.51 (1976)
Photon correlation spectroscopy
o Analogous to spatial information
from intensity interferometry,
photon correlation spectroscopy
does not reconstruct the shape of
the source spectrum, but “only”
gives linewidth information
QUANTUM OPTICS
R. Loudon
The
Quantum
Theory of
Light (2000)
Information content of light. III
D.Dravins, ESO Messenger 78, 9 (1994)
OWL Instrument Concept Study
The Road to Quantum Optics
High-Time Resolution
Astrophysics
HIGHEST TIME RESOLUTION,
REACHING QUANTUM OPTICS
• Other instruments cover seconds and
milliseconds
• QUANTEYE will cover milli-, micro-, and
nanoseconds, down to the quantum limit !
MILLI-, MICRO- & NANOSECONDS
•
•
•
•
•
•
•
•
•
•
Millisecond pulsars ?
Variability near black holes ?
Surface convection on white dwarfs ?
Non-radial oscillations in neutron stars ?
Surface structures on neutron-stars ?
Photon bubbles in accretion flows ?
Free-electron lasers around magnetars ?
Astrophysical laser-line emission ?
Spectral resolutions reaching R = 100 million ?
Quantum statistics of photon arrival times ?
p-mode oscillating neutron star
12
15
Y
Non-radial oscillations in neutron stars
McDermott, Van Horn & Hansen, ApJ 325, 725 (1988)
MAIN PREVIOUS LIMITATIONS
• CCD-like detectors:
Fastest practical frame rates: 1 - 10 ms
• Photon-counting detectors:
Limited photon-count rates: ≳ 100 kHz
5 x 5 array of 20 μm diameter APD detectors (SensL, Cork)
32x32 Single Photon Silicon Avalanche Diode Array
Quantum Architecture Group, L'Ecole Polytechnique Fédérale de Lausanne
PRELIMINARY OPTICAL DESIGN
G.Naletto, F.Cucciarrè, V.Da Deppo
Dept. of Information Engineering, Univ. of Padova
ISSUES
* How to photon-count @ 1 GHz?
* Large OWL images & Small APD detectors
CHOSEN CONSTRAINT
* Design within existing detector technologies
PRELIMINARY OPTICAL DESIGN
FEASIBILITY OF CONCEPT
* Slice OWL pupil into 100 segments
* Focus light from each pupil segment
by one in an array of 100 lenses
* Detect with an array of 100 APD’s
The collimator
The collimator-lens system magnifies 1/60 times
(collimator focal length = 600 mm, lens focal length = 10 mm),
giving a nominal spot size of 50 m (1 arcsec source).
Light collection with a lens array
Each lens has a square aperture, 10 mm side
The beam section is an annulus, with 100 mm external diameter
Array lens mounting concept
…
TDC-1
24 MHz
27bit
BUS
Storage 1
START
TDC-2
START
…
Photons
SPAD1
SPAD2
SPAD3
SPAD4
TDC-25
Control logic
(FPGA)
GPS
receiver
Creates the START
signal for the time to
digital converters from
the reference clock
E/O converter
PLL
…
START
20Mhz
H-MASER
fiber
E/O Converter
Reference Clock
DESIGN CHALLENGES
* Imaging with GHz photon-count rates?
* Spectroscopic imaging?
* Megapixel detector arrays?
•
•
“ULTIMATE” DATA RATES
* 1024 x 1024 imaging elements
@ 100 spectral & polarization channels
* Each channel photon-counting
@ 10 MHz, 1 ns time resolution
* Data @ 1015 photon time-tags per second
= 1 PB/s (Petabyte, 1015 B)
= some EB/h (Exabyte = 1018 B)
INSTRUMENT DESIGN ISSUES
• Telescope mechanical stability ?
(small and well-defined vibrations, etc.)
• Temporal structure of stray light ?
(scattered light may arrive with systematic timelags)
• Atmospheric intensity scintillation ?
(ELT entrance pupils are complex)
INSTRUMENTATION PHYSICS
• Physics of photon detection ?
(photons are never studied – one studies only
photoelectrons which obey other quantum statistics)
• Physics of photon manipulation ?
(does adaptive optics affect photon statistics?)
• Physics of photon propagation ?
(statistics change upon passing a beamsplitter)
Advantages of very large telescopes
Atmospheric
intensity
scintillation
D.Dravins, L.Lindegren, E.Mezey, A.T.Young, PASP 109, 610 (1998)
Advantages of very large telescopes
Telescope diameter
Intensity <I>
Second-order
correlation <I2>
Fourth-order photon
statistics <I4>
3.6 m
1
1
1
8.2 m
5
27
720
21
430
185,000
50 m
193
37,000
1,385,000,000
100 m
770
595,000
355,000,000,000
4 x 8.2 m
Precursors to ELT’s?
MAGIC
17 m diameter
La Palma
Studying rapid variability
Skinakas Observatory 1.3 m telescope, Oct.2004; OPTIMA (MPE) + QVANTOS Mark II (Lund)
Simulated Crab pulsar observations
with MAGIC
...
Photons have many properties…
ORBITAL ANGULAR
MOMENTUM !
Photon Orbital Angular Momentum
For any given l, the beam has l
intertwined helical phase fronts.
For helically phased beams, the
phase singularity on the axis
dictates zero intensity there.
The cross−sectional intensity
pattern of all such beams has
an annular character that persists
no matter how tightly the beam
is focused.
M.Padgett, J.Courtial, L.Allen, Phys.Today May 2004, p.25
Photon Orbital Angular Momentum
Spin
Orbital angular momentum
Although polarization enables only two photon spin states,
photons can exhibit multiple orbital-angular-momentum
eigenstates, allowing single photons to encode much more information
Martin Harwit(e.g., ApJ 597, 1266 (2003)
Photon Orbital Angular Momentum
At microscopic level, interactions have been observed
with helical beams acting as optical tweezers.
A small transparent particle was confined away from
the axis in the beam's annular ring of light.
The particle's tangential recoil due to the helical phase
fronts caused it to orbit around the beam axis.
At the same time, the beam's spin angular momentum
caused the particle to rotate on its own axis.
M.Padgett, J.Courtial, L.Allen, Phys.Today May 2004, p.25
Prototype
POAM
instrument
F. Tamburini,
G. Umbriaco,
G. Anzolin
Univ. of Padova
The Fork Hologram
Thanks to: Anton Zeilinger group
Institute of Experimental Physics
University of Vienna
The first three orders: l=0,1,2
l=2
l=1
l=0
The
End