Coherent Solution for Carrier Envelope Phase Stabilization

The new Micra-CEP from Coherent, Inc. is a unique, system for generating carrier envelope phase (CEP) stabilized ultrafast laser pulses.

The system combines Coherent's highly flexible and stable broadband ultrafast Micra laser with a carrier envelope phase detection module and fast feedback electronics. By active feedback control of the laser, the CEP stabilizer locks the phase velocity of the oscillating light field to the group velocity of the pulse envelope. Thus for ultrashort pulses consisting of only a few optical cycles, the peak of the oscillating electric field can be maximized under the pulse envelope.

At the heart of the CEP module is a non-linear interferometer. This unit uses a photonic crystal fiber to generate an octave-spanning optical spectrum. The red end of this spectrum is frequency-doubled and combined with the green end of this same broad spectrum. The resultant beat frequency is sensed by a fast photodetector that provides the CEP feedback signal.  After suitable processing, this signal is then used to control a fast cavity mirror actuator inside the Micra laser and thereby control the carrier phase. The Micra with CEP stabilizer is a powerful and flexible broadband laser source for the emerging fields of attosecond research, high harmonic generation, optical clocks and coherent control.