Simple method for frequency locking of an extended-cavity diode laser

Area of Science:

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

Background:

• Extended-cavity diode lasers (ECDLs) are crucial for applications requiring narrow linewidth and tunable output.
• Precise frequency control of lasers is essential for atomic spectroscopy and quantum information processing.
• Locking laser frequencies to atomic transitions provides a stable and accurate reference.

Purpose of the Study:

• To develop an extended-cavity tunable diode laser system with enhanced stability and output power.
• To achieve convenient and robust locking of the laser frequency to Rubidium (Rb) atomic transition lines.
• To demonstrate a wide frequency detuning range and high short-time linewidth stability.

Main Methods:

• Utilized an extended-cavity diode laser architecture with flat-mirror feedback.
• Implemented a frequency self-locking mechanism with weak feedback for stability.
• Employed a two-step locking procedure for precise frequency tuning and locking to Rb transitions.

Main Results:

• Achieved a laser system with a small linewidth and high output power (>90% of free-running power).
• Demonstrated a continuous frequency detuning range exceeding 900 MHz.
• Obtained short-time linewidth stability better than 0.4% and robust frequency locking.

Conclusions:

• The developed extended-cavity diode laser system provides a stable, tunable, and high-power source.
• The two-step locking procedure allows for convenient and precise frequency control for Rb atomic transitions.
• The system's ruggedness and stability make it suitable for demanding spectroscopic and quantum applications.