Control of the VCSEL spectrum by dual microwave frequency modulation

Area of Science:

• Optoelectronics
• Laser Physics
• Atomic Clocks

Background:

• Vertical-cavity surface-emitting lasers (VCSELs) are crucial components in various optical systems.
• Controlling VCSEL spectral properties is essential for applications like atomic clocks.
• Coherent population trapping (CPT) effects are utilized for high-precision frequency standards.

Purpose of the Study:

• To introduce and analyze a new method for controlling VCSEL optical spectra.
• To demonstrate experimental control over spectral sideband power asymmetry.
• To investigate carrier suppression for enhanced frequency stability in CPT-based atomic clocks.

Main Methods:

• Simultaneous modulation of the VCSEL injection current at single and doubled frequencies.
• Experimental investigation of spectral characteristics and sideband power.
• Analysis of carrier suppression techniques.

Main Results:

• Successful control of the power asymmetry of first-order sidebands was experimentally demonstrated.
• Effective suppression of the carrier signal was achieved using the proposed modulation method.
• The method shows potential for improving the frequency stability of atomic clocks.

Conclusions:

• The proposed dual-frequency current modulation offers precise control over VCSEL spectra.
• This technique is beneficial for enhancing the performance of atomic clocks utilizing CPT.
• The ability to manage sideband asymmetry and carrier suppression advances laser control methodologies.