A novel relative rotation sensor based on slow light is proposed and analysed. A theoretical analysis shows that the high sensitivity of the proposed rotation sensor is achieved through an electromagneticaIly-induced-transparency medium. Unlike the tradition detection method, the idea of rotation sensing is to detect group delay between counterpropagating wave packets. It can be used to realize an ultra-precise rotation sensor.
The operation of an ultra-narrow bandwidth optical filter based on the 5P3/2→5D3/2 excited-state transition in rubidium vapor is reported. The 5D3/2 state is excited by a circularly polarized pump beam at 780 nm from a diode laser. The filter displays a single 398-MHz bandwidth at a peak transmission of 9.0%, which is narrower than the Doppler bandwidth. The dependence of peak transmission on the pump intensity and cell temperature is also given.