Extended Data Fig. 3: Optimization of ISCL Operation.
From: Optical atomic clock interrogation using an integrated spiral cavity laser
a, Frequency noise spectra measured at a variety of chip-coupled optical powers. The line noise at 180 Hz and 300 Hz reduces with optical power. However, at 5.1 mW, the broadband noise level increases sharply. b, Noise at the power line frequencies of 60 Hz, 180 Hz, and 300 Hz plotted versus the on-chip optical power. The measured power line noise at all three frequencies decreases with increasing power. c, Fractional frequency noise of the ISCL across the same range of optical powers previously tested. Changes in optical power lead to competing effects in the stability of the laser at both short and longer averaging times. d, Fractional frequency noise versus optical power for averaging times of 1 ms and 30 ms. The optimum chip-coupled power is near 4.1 mW.
