High precision frequency calibration of tunable diode lasers stabilized on an internally coupled Fabry-Perot...

Area of Science:

• Atomic and Molecular Physics
• Optical Spectroscopy
• Laser Physics

Background:

• High-precision molecular spectroscopy requires accurate frequency calibration.
• Tunable diode lasers offer potential for high-resolution spectral analysis.
• Fabry-Perot interferometers are key components in optical frequency stabilization.

Purpose of the Study:

• To derive the exact relationship between a tunable diode laser frequency and a reference laser's fringe number.
• To describe a convenient calibration procedure for molecular spectroscopy.
• To achieve a frequency accuracy of 5 x 10(-5) cm(-1) at 10 micrometers.

Main Methods:

• Frequency locking a tunable diode laser to an internally coupled Fabry-Perot interferometer (icFPI).
• Simultaneous coupling of an iodine-stabilized He-Ne reference laser into the icFPI for spectral calibration.
• Derivation of the precise mathematical relation between the diode laser frequency and He-Ne fringe count.

Main Results:

• An exact relation between the diode laser frequency and the He-Ne fringe number was derived.
• A practical calibration procedure was established.
• A frequency accuracy of 5 x 10(-5) cm(-1) at 10 micrometers was demonstrated.

Conclusions:

• The described method provides a highly accurate and convenient calibration for high-precision molecular spectroscopy.
• The use of an icFPI and a He-Ne reference laser enables precise frequency determination.
• This technique is valuable for applications demanding exacting spectral measurements.