Locking Multi-Laser Frequencies to a Precision Wavelength Meter: Application to Cold Atoms

Area of Science:

• Atomic, Molecular, and Optical Physics
• Laser Spectroscopy
• Quantum Optics

Background:

• Precise laser frequency control is crucial for atomic physics experiments.
• External cavity diode lasers offer tunability but require stabilization.
• Magneto-optical traps (MOTs) are essential for atom manipulation.

Purpose of the Study:

• To demonstrate simultaneous frequency stabilization of two 780-nm lasers.
• To characterize the laser lock performance and identify noise sources.
• To apply the stabilized lasers for creating a magneto-optical trap near an optical cavity.

Main Methods:

• Simultaneous frequency locking of two external cavity diode lasers using a precision wavelength meter (WLM).
• Allan deviation measurements to quantify laser stability (σy=10⁻¹² at 1000 s).
• Heterodyne spectroscopy to analyze spectral profiles and noise contributions (white and flicker noise).

Main Results:

• Achieved high laser frequency stability with Allan deviation of 10⁻¹² at 1000 s.
• Measured WLM frequency drift of 2.0(4) MHz over 36 hours.
• Successfully demonstrated a magneto-optical trap (MOT) of ⁸⁷Rb atoms near a high-finesse optical cavity using the stabilized lasers.

Conclusions:

• The developed laser stabilization technique provides excellent frequency control for 780-nm lasers.
• The method is effective for applications like atom trapping near optical cavities.
• The technique operates over a broad wavelength range without requiring radio frequency components.