Transcript PPT - Rencontres de Moriond

Next generation nonclassical light sources
for gravitational wave detectors
Stefan Ast, Christoph Baune, Jan Gniesmer, Axel Schönbeck,
Christina Vollmer, Moritz Mehmet, Henning Vahlbruch, Hartmut
Grote, Lisa Kleybolte, Alexander Khalaidovski and Roman Schnabel
Institut für Laserphysik, Universität Hamburg
Albert-Einstein-Institut, Max-Planck-Institut für Gravitationsphysik
Institut für Gravitationsphysik der Leibniz Universität Hannover
Rencontres de Moriond
2015
The GEO 600 squeezed light source
The LIGO Scientific Collaboration, “A gravitational wave observatory operating
beyond the quantum shot-noise limit”, Nature Physics 7 (2011)
Stefan Ast
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The GEO 600 squeezed light source
Duty cycle:
85% (2011-2015)
Max. 3.7 dB
The LIGO Scientific Collaboration, “A gravitational wave observatory operating
beyond the quantum shot-noise limit”, Nature Physics 7 (2011)
Stefan Ast
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Einstein Telescope I – artistic layout
M Punturo et al, “The Einstein Telescope: a third-generation gravitational wave
observatory”, Class. Quantum Grav. 27 (2010)
Stefan Ast
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Einstein Telescope II – Interferometer designs
1550 nm
M Punturo et al, “The Einstein Telescope: a third-generation gravitational wave
observatory”, Class. Quantum Grav. 27 (2010)
Stefan Ast
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High conversion efficiency second harmonic generation
Ast et al. “High-efficiency frequency doubling of continuous-wave laser light“;
Optics Letters 36 (2011) No. 17
Rencontres de Moriond
2015
Improve SHG conversion efficiency
Stefan Ast
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Experimental setup – High conversion second harmonic generation
Conversion
measurement
Stefan Ast
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High efficiency second harmonic generation
Power Conversion:
1.1 W (1550 nm) ⟶ 1.05 W (775 nm)
Power meter error:
6 % total ⟶ inaccurate!
Stefan Ast
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SHG pump depletion
Stefan Ast
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Doubly-resonant squeezed light source at
1550 nm
Kleybolte, Master Thesis 2013
Rencontres de Moriond
2015
The GEO 600 squeezed light source
Stefan Ast
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Doubly resonant squeezing resonator @ 1550 nm
1 MHz
130 kHz
Stefan Ast
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Squeezing measurement in the audio band
12.3 dB
Squeezing at 1550 nm & strong enough
for third generation GW detectors
Mehmet et al. “Squeezed light at 1550 nm with a quantum noise reduction of 12.3 dB“;
Optics Express 19 (2011) No. 25
Stefan Ast
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Frequency conversion of squeezed light
Baune et al. arXiv:1503.02008
Rencontres de Moriond
2015
DECIGO & squeezing @ 532 nm
Sum Frequency Generation
532 nm
Kawamura et al, “The Japanese space gravitational wave antenna: DECIGO”,
Class. Quantum Grav. 28 (2011)
Stefan Ast
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Experimental setup – frequency conversion of squeezed light
Stefan Ast
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Squeezing measurement @ 532 nm
5 dB
Stefan Ast
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Summary
High-efficiency SHG
95% conversion efficiency @ 1550 nm
Doubly resonant squeezed light source
Maximum of 10 dB @ 1 MHz
7 dB @ 130 kHz
Squeezed light for 3. generation GWD
12.3 dB @ 1550 nm
Frequency up-conversion of squeezed light
5 dB @ 532 nm
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Thank you for your attention!
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Generation of squeezed light
Squeezed bandwidth
Parametric down conversion
Squeezing
bandwidth
Pump power enhancement
Squeezing enhancement
FSR
Problem: Rω limits the
bandwidth!
FSR=
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c
2nL
Finesse∝
π√R
1− R
Squeezed light source without squeezing resonator
S. Ast et al, Continuous-wave nonclassical light with gigahertz squeezing bandwidth,
Optics letters 37, 2367 (2012)
Outline
GHz bandwidth quantum states
Quantum Key Distribution
High-bandwidth quantum state generation
GHz bandwidth squeezed light
Experiment
GHz bandwidth entangled light
Squeezed light via the cascaded Kerr effect
An Odyssey to Kerr squeezing
New experimental approach
Cascaded Kerr squeezing
Experiment
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Experimental setup – Squeezed light at 1550 nm
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Kerr squeezing loss estimation
Based on 85 mW pump power at 358 MHz
9.5 dB
Estimated loss contributions
Type
61%
Homodyne efficiency
0.978
PD quantum efficiency
0.94
Optical path loss
-2 dB
Detection efficiency
0.88-0.92
Bow-tie internal loss
0.547
SEMC transmission
0.887
Total
0.39-0.41
Bow-tie internal loss
High 775 nm generation
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