Compact rubidium-stabilized multi-frequency reference source in the 1.55-μm region.

Area of Science:

• Photonics and Laser Technology
• Atomic Physics and Spectroscopy
• Optical Metrology

Background:

• Optical frequency combs (OFCs) are crucial for high-precision measurements.
• Stabilizing OFCs to atomic transitions ensures long-term frequency accuracy.
• Existing methods for generating stabilized OFCs can be complex and bulky.

Purpose of the Study:

• To demonstrate a compact and simple frequency-stabilized optical frequency comb.
• To achieve high frequency stability in the 1.56-μm wavelength region.
• To leverage rubidium atomic transitions for frequency stabilization.

Main Methods:

• Generation of an optical frequency comb using an electro-optic modulator in a Fabry-Perot cavity.
• Injection of the cavity with a fundamental frequency-stabilized laser.
• Frequency stabilization by probing rubidium atomic transitions at 780 nm via saturation absorption.
• Transfer of frequency stability to the 1.56-μm region using second-harmonic generation.

Main Results:

• Demonstration of a compact optical frequency comb spanning over 45 nm in the 1.56-μm region.
• Achieved frequency stability better than 2 kHz at 1560 nm and 1557 nm.
• Stability demonstrated over time scales from 1000 s to 2 days.
• Successful transfer of rubidium atomic transition stability to the target wavelength.

Conclusions:

• The developed technique provides a simple and effective method for generating a frequency-stabilized optical frequency comb.
• The compact nature of the system makes it suitable for various applications requiring precise optical frequencies.
• The high stability achieved opens possibilities for advancements in optical communications and metrology.