Locking laser frequency of up to 40  GHz offset to a reference with a 10  GHz electro-optic modulator

Area of Science:

• Photonics and Optical Engineering
• Laser Physics
• Applied Electromagnetics

Background:

• Precise control of laser frequencies is crucial for applications like optical communications and spectroscopy.
• Existing methods for generating frequency-offset lasers can be complex, costly, or lack stability.

Purpose of the Study:

• To demonstrate a simple, stable, and low-cost method for generating phase-coherent laser pairs with tunable frequency offsets.
• To achieve frequency offsets of up to 40 GHz using readily available components.

Main Methods:

• Utilizing a 10 GHz waveguide-type electro-optic modulator (EOM) to generate optical sidebands.
• Controlling the power of the radio frequency driving the EOM to generate first- to fourth-order sidebands.
• Scanning the driving frequency across the 10 GHz bandwidth to achieve an 80 GHz tuning range (-40 to 40 GHz).
• Locking a generated sideband to a reference laser frequency.

Main Results:

• Successfully demonstrated laser frequency locking with offsets up to 40 GHz.
• Generated a wide tuning range of 80 GHz by controlling EOM sidebands.
• Achieved simple, stable, and low-cost generation of phase-coherent laser pairs.

Conclusions:

• The proposed method offers a practical solution for generating frequency-offset laser pairs.
• This technique is suitable for applications requiring stable, phase-coherent lasers with specific frequency separations.
• The simplicity and low cost make this method highly attractive for various scientific and technological fields.