Mid-infrared Ring Interband Cascade Laser: Operation at the Standard Quantum Limit

Area of Science:

• Quantum optics
• Laser physics
• Mid-infrared technology

Background:

• Precision applications in the mid-infrared (MIR) are limited by quantum noise characteristics.
• Interband cascade lasers (ICLs) are crucial for MIR applications (3-6 μm), with novel ring-cavity designs showing promise.
• Thorough analysis of ICL noise behavior, including shot-noise limit reduction, is essential.

Purpose of the Study:

• To comprehensively characterize the noise properties of 3.8 μm-emitting, continuous-wave (CW) ring interband cascade lasers (ICLs) at room temperature.
• To investigate the bias-dependent intensity noise power spectral density and relative intensity noise.
• To assess the potential for achieving shot-noise-limited performance.

Main Methods:

• Fabrication and characterization of CW ring ICLs operating at 3.8 μm.
• Measurement of bias-dependent intensity noise power spectral density.
• Analysis of relative intensity noise (RIN).

Main Results:

• Demonstrated shot-noise-limited statistics for Fourier frequencies above 100 kHz.
• Detailed characterization of intensity noise features in room-temperature CW ring ICLs.
• Identified the potential for enhanced sensitivity in precision applications.

Conclusions:

• Room-temperature CW ring ICLs can achieve shot-noise-limited performance, crucial for high-sensitivity MIR applications.
• These lasers enhance sensitivity in interferometry and advanced spectroscopy.
• The results are significant for quantum optics, enabling studies of states below the shot-noise limit, like squeezed states.