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High-bandwidth squeezed light at 1550 nm from a compact monolithic PPKTP cavity
Stefan Ast1, Moritz Mehmet, Roman Schnabel
1Max Planck Institute for Gravitational Physics, Albert Einstein Institute, Leibniz Universität Hannover, Hannover, Germany.
Optics Express
|June 6, 2013
Summary
Researchers generated broadband squeezed vacuum states of light, achieving 4.8 dB quantum noise reduction. This advancement in squeezed light generation offers new possibilities for high-speed quantum key distribution.
Area of Science:
- Quantum optics
- Non-linear optics
Background:
- Squeezed vacuum states are crucial for quantum information processing.
- Broadband squeezed light generation is essential for high-speed quantum communication.
Purpose of the Study:
- To generate broadband squeezed vacuum states of light at 1550 nm.
- To characterize the quantum noise reduction over a wide frequency range.
- To explore applications in high-speed quantum key distribution.
Main Methods:
- Utilized a custom-designed periodically-poled potassium titanyl phosphate (PPKTP) crystal for optical parametric amplification.
- Employed two homodyne detectors with varying quantum efficiencies and bandwidths for characterization.
- Measured squeezing via broadband quantum noise reduction.
Main Results:
- Achieved broadband quantum noise reduction of up to 4.8 dB from 5 MHz to 1.2 GHz sideband frequency.
- Measured squeezing values up to 4.8 dB (5-100 MHz) and 3 dB (100 MHz-1.2 GHz).
- Identified detection loss as a limiting factor for measurements.
Conclusions:
- Demonstrated GHz bandwidth squeezed light generation.
- Proposed an improved detection scheme to measure higher squeezing levels (up to 10 dB over 1 GHz).
- Highlighted the potential for high-speed quantum key distribution.
