Phase-locked, low-noise, frequency agile titanium:sapphire lasers for simultaneous atom interferometers

We demonstrate a laser system consisting of a >1.6 W titanium:sapphire laser that is phase locked to another free-running titanium:sapphire laser at a wavelength of 852 nm with a phase noise of -138 dBc/Hz at 1 MHz from the carrier, using an intracavity electro-optic phase modulator. The residual phase variance is 2.5 x 10(-8) rad2 integrated from 1 Hz to 10 kHz. This system can phase-continuously change the offset frequency within 200 ns with frequency steps up to 4 MHz. Simultaneous atom interferometers can make full use of this ultralow phase noise in differential measurements, where influences from the vibration of optics are greatly suppressed in common mode.