Optical deceleration of atomic hydrogen*

We will discuss a method for laser slowing of atomic hydrogen.  The technique proceeds by first exciting a cryogenic beam of atomic hydrogen to the metastable 2S state.  Atoms from this beam are then loaded into an optical lattice which is tuned near the 2S-4P transition.  The lattice is moving at approximately the mean velocity of the beam and is capable of trapping atoms with velocities +-10 m/s of this velocity.  The lattice is then rapidly decelerated using electro-optics to slow the trapped atoms.  With this technique, we have observed accelerations of -10^9 m/s^2, and total velocity changes of about -15 m/s.