Quantum theory of a spaser-based nanolaser

Area of Science:

• Quantum optics
• Nanolaser technology
• Plasmonics

Background:

• Spaser-based nanolasers offer unique optical properties.
• Understanding their quantum behavior is crucial for device development.
• The bad-cavity approximation simplifies complex quantum systems.

Purpose of the Study:

• To develop a quantum theory for spaser-based nanolasers under the bad-cavity approximation.
• To analyze the coherence properties and photon statistics.
• To investigate the behavior of amplitude fluctuations near the generation threshold.

Main Methods:

• Calculation of first- and second-order correlation functions (g(1)(τ) and g(2)(τ)).
• Determination of the average number of cavity plasmons.
• Analysis of spectral line narrowing and coherence preservation.

Main Results:

• The average number of plasmons is near unity at the generation threshold.
• Coherence is preserved in active atoms, unlike in good-cavity lasers.
• Damped oscillations in g(2)(τ) indicate interconnected amplitude fluctuations.

Conclusions:

• The study elucidates fundamental operating principles of spaser-based nanolasers.
• Nears the threshold, unique quantum phenomena govern nanolaser behavior.
• Results provide a basis for designing and optimizing future nanolasers.