Tomographic characterization of OPO sources close to threshold

Area of Science:

• Quantum optics
• Quantum information science

Background:

• Characterizing quantum states is crucial for quantum technologies.
• Degenerate below-threshold type-I optical parametric oscillators (OPOs) are sources of non-classical light.

Purpose of the Study:

• To characterize the output of a degenerate below-threshold type-I OPO using pattern function quantum homodyne tomography (QHT).
• To identify deviations from expected quantum states, such as Gaussian thermal states.

Main Methods:

• Utilized pattern function quantum homodyne tomography (QHT).
• Analyzed the output of a degenerate below-threshold type-I OPO.
• Calculated photon number distributions and Kurtosis from homodyne data.

Main Results:

• Recovered photon number distributions deviated significantly from Gaussian thermal states.
• Kurtosis analysis of the homodyne data confirmed these deviations.
• Demonstrated the sensitivity of QHT in detecting non-classical features.

Conclusions:

• QHT is a powerful tool for revealing unexpected features in quantum states.
• The output of the studied OPO does not conform to simple Gaussian thermal state models.
• QHT provides a robust method for quantum state characterization.