SPARQL

Sequential Parametric Amplification: Quantum Technology with Multimode Light.                                                                                                                                          2021 QuantERA call for Quantum Phenomena and Resources (QPR).

Parametric amplification plays an important role in many quantum technologies. An optical parametric amplifier is as indispensable as an operational amplifier in classical electronics. The noise of a parametric amplifier is squeezed vacuum, the workhorse of quantum optics. By placing two parametric amplifiers in sequence one obtains the so-called SU(1,1) interferometer, theoretically proposed decades ago but realized in experiment only recently. This is an example of an active interferometer; it outperforms conventional passive interferometers and provides new topologies suitable for many quantum applications.

Confirmed by recent experiments, sequential parametric amplification provides:

- phase sensitivity beyond the shot-noise limit;

- possibility of ultra-broadband (up to 120THz) optical homodyne detection by using the second amplifier as an optical homodyne device;

- tolerance to detection loss provided that the second amplifier gain is sufficiently high.

SPARQL will develop multimode sequential parametric amplification and use it for current needs of quantum technology. We will consider parametric amplification of both spatial/angular modes and temporal/frequency modes. As a result, we will implement the following techniques, with tolerance to loss:

- squeezing-enhanced imaging and microscopy;

- squeezing-enhanced Raman spectroscopy and wide-field microscopy, with orders of magnitude speedup due to the multimode structure;

- squeezing-enhanced frequency-multimode quantum key distribution.

Moreover, we will address a new area of non-Gaussian frequency-multimode quantum sensing to overcome limits of squeezed-enhanced sensing, spectroscopy and microscopy.

Wide-angle SU(1,1) interferometer. Emission from optical parametric amplifier OPA1 is imaged into OPA2, which provides uniform amplification/deamplification for all angles. A sample is placed into the far or near field, depending on the task. For near-field imaging, additional lenses are used.

Contact