The AOM works at high diffraction orders regime, it diffracts the incident beam into different orders, and reflects about 1% from the front face. The ω and Ω are incident laser frequency and rf driving frequency of AOM, respectively.
The calculated light intensities of different diffraction order versus incident angle. High orders (n > 1) diffracted light efficiencies multiplied by proper factors are shown in the inset for clarity. The parameters used are , , , Δn = 4.0 × 10−4, and rf frequency is 253 MHz.
(a) Diffraction efficiency of several sidebands of the AOM versus driving frequency. (b) Diffraction efficiency of some fix frequency shift diffraction components of the AOM versus sideband. Both data taken with horizontally polarized diode laser and with the same AOM driver rf power .
Beat-note spectrum of the ±6 diffraction orders light at 12-fold of the driving rf (253 MHz). The measured line width (FWHM) of the beat-note is 1 Hz without averaging, which is limited by the resolution bandwidth of the spectrum analyzer (1 Hz).
CPT experimental apparatus. PBS and PD denote polarizing beam splitter and photo-detector. The bubble shows the lin ⊥ lin CPT transitions involving D1 line energy levels of 87 Rb as one of the sample atoms.
A typical lin ⊥ lin CPT signal in 85Rb (a) and 87Rb (b) on the D1 line. The atomic vapor cell temperature, buffer gas pressure, probe, and pump beam intensity are 65°C, 2 Torr, , and , respectively in (a) and 59°C, 20 Torr, , and , respectively in (b). Both signals in (a) and (b) obtained by PD1 (probe beam), and a 24 μT magnetic field was created in a direction parallel to the propagation of the beams to lift Zeeman levels.
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