Transmission spectra of the cavity when AM of the ODT is applied. The red dots indicate transmission of the cavity (normalized) versus frequency of AM with a depth of 50%. The blue curve is a Lorentzian fitting. The black dots correspond to the results without AM. Panel (a) is for radial direction and panel (b) is the axial direction. Two peaks at 2.76 ± 0.01 kHz and 5.58 ± 0.02 kHz in panel (a) and 33.0 ± 0.8 Hz and 60.1 ± 0.6 Hz in panel (b) correspond to the trap frequency and its second harmonic in radial and axial directions, respectively. The green line in panel (b) shows the measured level of transmission without an AM.