Abstract: A system for gravity measurement includes one or more atom sources, two or more laser beams, and a polarizing beamsplitter and a retro-reflection prism assembly. The one or more atom sources is to provide three ensembles of atoms. The two or more laser beams is to cool or interrogate the three ensembles of atoms. The polarizing beamsplitter and the retro-reflection prism assembly are in a racetrack configuration. The racetrack configuration routes the two or more laser beams in opposing directions around a loop topology, intersecting the three ensembles of atoms with appropriate polarizations chosen for cooling or interferometer interrogation. The three ensembles of atoms are positioned coaxially when interrogated.

Abstract: A system for controlling a phase measurement in an atom interferometer comprising one or more lasers, a processor, and a memory. The one or more lasers are for providing interrogating beams. A first cloud of atoms and a second cloud of atoms traverse an interrogating region of the atom interferometer in substantially opposite directions. The interrogating beams interact substantially simultaneously with both atoms in the first cloud and atoms in the second cloud. The first cloud of atoms and the second cloud of atoms interact with each of the interrogating beams in a different order. The processor is configured to determine a phase adjustment offset of at least one interrogating beam based at least in part on one or more past interactions of one or more interrogating beams with either the first cloud of atoms or the second cloud of atoms.

Abstract: A system for controlling a phase measurement in an atom interferometer comprising one or more lasers, a processor, and a memory. The one or more lasers are for providing interrogating beams. A first cloud of atoms and a second cloud of atoms traverse an interrogating region of the atom interferometer in substantially opposite directions. The interrogating beams interact substantially simultaneously with both atoms in the first cloud and atoms in the second cloud. The first cloud of atoms and the second cloud of atoms interact with each of the interrogating beams in a different order. The processor is configured to determine a phase adjustment offset of at least one interrogating beam based at least in part on one or more past interactions of one or more interrogating beams with either the first cloud of atoms or the second cloud of atoms.

Abstract: A system for gravity measurement includes one or more atom sources, two or more laser beams, and a polarizing beamsplitter and a retro-reflection prism assembly. The one or more atom sources is to provide three ensembles of atoms. The two or more laser beams is to cool or interrogate the three ensembles of atoms. The polarizing beamsplitter and the retro-reflection prism assembly are in a racetrack configuration. The racetrack configuration routes the two or more laser beams in opposing directions around a loop topology, intersecting the three ensembles of atoms with appropriate polarizations chosen for cooling or interferometer interrogation. The three ensembles of atoms are positioned coaxially when interrogated.

Abstract: The device for producing laser-cooled atoms comprises a two dimensional trap or a three-dimensional trap, or a combination of two- and three-dimensional traps. The two-dimensional trap comprises: three or more permanent magnets arranged around a perimeter of a loop, wherein a plane of the loop is perpendicular to a free axis of the two-dimensional atom trap, and the three or more permanent magnets bracket an internal volume of the two-dimensional atom trap; and one or more laser beam input ports enabling access for one or more laser beams to the internal volume of the two-dimensional atom trap.

Abstract: A system for controlling a phase measurement in an atom interferometer comprising one or more lasers, a processor, and a memory. The one or more lasers are for providing interrogating beams. A first group of atoms and a second group of atoms traverse an interrogating region of the atom interferometer in substantially opposite directions. The interrogating beams interact substantially simultaneously with both atoms in the first group and atoms in the second group. The first group of atoms and the second group of atoms interact with each of the interrogating beams in a different order. The processor is configured to determine a phase adjustment offset of at least one interrogating beam based at least in part on one or more past interactions of one or more interrogating beams with either the first group of atoms or the second group of atoms.

Abstract: The device for producing laser-cooled atoms comprises a two dimensional trap or a three-dimensional trap, or a combination of two- and three-dimensional traps. The two-dimensional trap comprises: three or more permanent magnets arranged around a perimeter of a loop, wherein a plane of the loop is perpendicular to a free axis of the two-dimensional atom trap, and the three or more permanent magnets bracket an internal volume of the two-dimensional atom trap; and one or more laser beam input ports enabling access for one or more laser beams to the internal volume of the two-dimensional atom trap.

Abstract: The device for producing laser-cooled atoms comprises a two dimensional trap or a three-dimensional trap, or a combination of two- and three-dimensional traps. The two-dimensional trap comprises: three or more permanent magnets arranged around a perimeter of a loop, wherein a plane of the loop is perpendicular to a free axis of the two-dimensional atom trap, and the three or more permanent magnets bracket an internal volume of the two-dimensional atom trap; and one or more laser beam input ports enabling access for one or more laser beams to the internal volume of the two-dimensional atom trap.

Abstract: A method for optimizing a dc operating drive current of a laser diode is presented. Lasers of a particular type are characterized in terms of the dependency of certain parameters on temperature and of the minimum bias current required for adequate laser speed. The minimum bias current is determined using the operating bias current minus the threshold current all normalized by the threshold current. For individual laser diodes, the threshold current and slope efficiency are obtained at various temperatures to allow calculation at operating temperatures of interest. The minimum laser bias current for speed can then be determined over the operating temperature range. This may be done by setting the optical power to the highest value calculated using this minimum acceptable bias criterion over the operating temperature range. The ac and dc laser driver current sourcing requirements may be computed to ensure laser and module compatibility.

Abstract: Method and apparatus of attenuating an optical signal without adding extra components is presented. The drive current of the optical signal source is set to meet a predetermined bandwidth requirement and exceed a predetermined amplitude requirement. An optical isolator that is used to prevent back-reflections from reaching the optical signal source is used to achieve the desired amount of attenuation. More specifically, the invention includes controlling the attenuation by tuning an angle ? between the transmission axis of a polarizer that is part of the optical isolator and the original polarization state of the optical signal. By increasing the angle ?, the amount of attenuation is increased; by decreasing the angle ?, the amount of attenuation is decreased. The invention allows continuous tuning of the angle ?.

Abstract: A modular TOSA that is compatible with multiple optical fiber connector standards and a method of making the TOSA are presented. With the invention, a modular TOSA can be made compatible with different connector standards by switching the nose assembly while keeping the port assembly design and the adapter assembly design constant. The nose assembly that is compatible with the desired connector standard is selected from a group of nose assemblies, which are designed to be coupled with the same port assembly but having different connector standards.

Abstract: Method and apparatus of attenuating an optical signal without adding extra components is presented. The drive current of the optical signal source is set to meet a predetermined bandwidth requirement and exceed a predetermined amplitude requirement. An optical isolator that is used to prevent back-reflections from reaching the optical signal source is used to achieve the desired amount of attenuation. More specifically, the invention includes controlling the attenuation by tuning an angle &thgr; between the transmission axis of a polarizer that is part of the optical isolator and the original polarization state of the optical signal. By increasing the angle &thgr;, the amount of attenuation is increased; by decreasing the angle &thgr;, the amount of attenuation is decreased. The invention allows continuous tuning of the angle &thgr;.

Abstract: A modular TOSA that is compatible with multiple optical fiber connector standards and a method of making the TOSA are presented. With the invention, a modular TOSA can be made compatible with different connector standards by switching the nose assembly while keeping the port assembly design and the adapter assembly design constant. The nose assembly that is compatible with the desired connector standard is selected from a group of nose assemblies, which are designed to be coupled with the same port assembly but having different connector standards.