Temperature-scanning saturation cavity ring-down spectrometry for Doppler-free spectroscopy

Area of Science:

• Atomic and Molecular Physics
• Spectroscopy
• Quantum Optics

Background:

• Saturation cavity ring-down spectroscopy (SCRDS) is a key technique for high-precision frequency measurements.
• Traditional SCRDS often requires complex optical cavity-length stabilization systems.
• Achieving ultra-low uncertainties in spectroscopic measurements is crucial for fundamental science and applications.

Purpose of the Study:

• To present a simplified implementation of SCRDS.
• To demonstrate a novel method for cavity-length control using temperature scanning.
• To measure absolute frequencies of specific transitions in 12CH4 with enhanced accuracy.

Main Methods:

• Implemented SCRDS by temperature scanning the cavity length, avoiding piezoelectric actuators (PZT).
• Utilized Doppler-free spectroscopy principles for precise measurements.
• Targeted R6F1 of the 2v3 and Q9A1 of the 2v2 + v3 bands of 12CH4.

Main Results:

• Determined the absolute frequency of the R6F1 transition (2v3 band) of 12CH4 to be 182 185 269.362(20) MHz.
• Measured the absolute frequency of the Q9A1 transition (2v2 + v3 band) of 12CH4 to be 182 187 617.543(39) MHz.
• Achieved measurement accuracy improvement of 3-4 orders of magnitude compared to conventional methods.

Conclusions:

• The temperature-scanning cavity-length method provides a simpler and effective approach to SCRDS.
• This technique significantly enhances the accuracy of absolute frequency measurements for molecular transitions.
• The results offer valuable data for 12CH4 spectroscopy and related fields.