A proposal for detecting weak electromagnetic waves around 2.6 μm wavelength with Sr optical clock

Infrared signal detection is widely used in many fields. Due to the detection principle, however, the accuracy and range of detection are limited. Thanks to the ultra stability of the 87 Sr optical lattice clock, external infrared electromagnetic wave disturbances can be responded to. Utilizing the ac Stark shift of the clock transition, we propose a new method to detect infrared signals. According to our calculations, the theoretical detection accuracy in the vicinity of its resonance band of 2.6 μm can reach the order of 10 −14 W, while the minimum detectable signal of common detectors is on the order of 10 −10 W.