Laser frequency stabilization by modulation transfer spectroscopy and balanced detection of molecular iodine for laser cooling of ¹⁷⁴Yb

We report laser frequency stabilization by the combination of modulation transfer spectroscopy and balanced detection of a relatively weak hyperfine transition of the R(158)25-0 line of molecular iodine (127I2), which is used as a new frequency reference for laser trapping and cooling of 174Yb on the 1S0 - 3P1 transition. The atomic cloud is characterized by time-of-flight measurements, and an on-resonance optical depth of up to 47 is obtained. We show laser noise reduction and characterize the short -term laser frequency instability by the Allan deviation of the laser fractional frequency. The minimum measured value is 3.9 x10-13 at 0.17 s of averaging time. (c) 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement