Electromagnetically induced transparency and optical switching in a rubidium cascade system.

Electromagnetically induced transparency is observed in a mismatched-wavelength cascade system with a room-temperature rubidium vapor cell. A cw probe laser beam monitors the 5S(1/2) ? 5P(3/2) transition while another cw laser couples the 5P(3/2) state to a higher excited state. The ratio of the observed Rabi frequencies for coupling to the 5P(3/2) ? 8D(3/2), (5/2) transitions agrees well with that predicted by use of the transition oscillator strengths.

Calibration of laser frequency scan with an electro-optic modulator.

An electro-optically modulated laser beam was used to excite the Yb1S0 (6s ) 2?3P1 (6 s 6 p ) transition. Fluorescence was recorded as the laser frequency was scanned across the transition. Each isotope generated multiple peaks in the spectrum separated by the modulation frequency that permitted the frequency scan to be calibrated.