A tunable external cavity laser using a micromachined silicon flexure for atomic spectroscopy

This paper reports a novel external cavity diode laser system for applications in atomic physics that employs a micromachined silicon flexure to sweep the laser frequency near the rubidium absorption spectrum. The advantages of using a silicon flexure are its simple microfabrication process and reduction of the overall size of the laser system. The results demonstrate the Rb-87, Rb-85 (rubidium) D-2 line absorption at 780 nm in an atomic optics test experiment. Our novel laser system design has a size of 26.3 x 20 x 20 mm. The wavelength can be tuned and swept from 780.2533 to 780.2344 nm equivalent to 9.31 GHz using only piezoelectric transducer PZT actuators integrated on the silicon flexure. The deflection of the silicon flexure is 157.45 nm. The advantage of combining a VHG and a silicon flexure is that the frequency can be coarsely tuned to 780.24 nm and swept at this center frequency with a range of 9.31 GHz by PZT. Moreover, the frequency fine tuning can be achieved by changing the VHG temperature to observe the rubidium spectrum. The laser output power is measured as 9.72 mW at 780.24385 nm.