A compact extended cavity laser using a micromachined silicon flexure for atomic spectroscopy

We report a novel compact extended cavity diode laser (ECDL) system for applications in atomic physics. It employs a 6.5 mm invar cavity, a volume holographic grating (VHG), and a micromachined silicon flexure integrated with a pair of piezoelectric transducer (PZT) actuators, and the overall laser system has a size of 26.3 mm × 20 mm × 20 mm. The advantages of using a silicon flexure are its high material rigidity and simple microfabrication process with designable displacement. The measured spring constant of the silicon flexure is 1.56 × 105 N/m, and its deflection is 157.45 nm. This displacement alters the laser cavity length, leading to a frequency tuning range of 9.31 GHz. A frequency tuning range of 11.6792 GHz can also be achieved by changing the VHG temperature, providing another fine tuning mechanism. The laser wavelength was swept between 780.2533 and 780.2344 nm, covering the rubidium D2 absorption peaks.