Coherent population trapping magnetometer by differential detecting magneto–optic rotation effect

A pocket coherent population trapping（CPT） atomic magnetometer scheme that uses a vertical cavity surface emitting laser as a light source is proposed and experimentally investigated.Using the differential detecting magneto–optic rotation effect,a CPT spectrum with the background canceled and a high signal-to-noise ratio is obtained.The experimental results reveal that the sensitivity of the proposed scheme can be improved by half an order,and the ability to detect weak magnetic fields is extended one-fold.Therefore,the proposed scheme is suited to realize a pocket-size CPT magnetometer.

Experimental demonstration of optical Bloch oscillation in electromagnetically induced photonic lattices

The optical Bloch oscillation(OBO)is an optical-quantum analogy effect that is significant for light field manipulations,such as light beam localization,oscillation and tunneling.As an intra-band oscillation,OBO was important for optical investigations in photonic lattices and atomic vapors over an extended period of time.However,OBO in reconfigurable platforms is still an open topic,even though tunability is highly desired in developing modern photonic techniques.Here we theoretically establish and experimentally demonstrate OBO in an electromagnet-ically induced photonic lattice with a ramping refractive index,established in a coherently-prepared three-level 85 Rb atomic vapor under the electromagnetically induced transparency condition.This is achieved by interfering two coupling beams with Gaussian profiles and launching a probe beam that exhibits OBO within the resulting lattice.The induced reconfigurable photonic lattice possesses a transverse gradient,due to the innate edges of Gaussian beams,and sets a new stage for guiding the flow of light in periodic photonic environments.Our results should motivate better understanding of peculiar physical properties of an intriguing quantum-optical analogy in an atomic setting.