Fiber-based acetylene-stabilized laser

We describe a fiber-based acetylene-stabilized laser, where light is coupled to free-space only to pass through the acetylene cell. The system is constructed using standard components, which makes the approach cost effective and straightforward to implement. The Doppler-free spectrum of acetylene is detected using a simple collinear pump-probe geometry, even without a lock-in amplifier, when the length of the optical path in the spectroscopy arrangement is dithered to cancel interference inevitably present in a fiber-based setup. The third-harmonic technique is used to lock the laser to an acetylene line. The method to cancel the interference can be conceivably used also in laser-stabilization in general.