Inertial sensor
An inertial sensor includes a dual atom interferometer. A moving standing light wave generation device in the dual atom interferometer generates M (3≤M) moving standing light waves. Each of the M moving standing light waves is generated by a pair of counter-propagating laser beams. The moving standing light wave generation device adjusts two-photon detuning of a pair of counter-propagating laser beams corresponding to each of N (2≤N<M) moving standing light waves out of the M moving standing light waves such that the difference between an interferometric phase corresponding to one atomic beam obtained by interfering with the M moving standing light waves and an interferometric phase corresponding to the other atomic beam obtained by interfering with the M moving standing light waves stays constant.
1 . An inertial sensor comprising:
a first atomic beam generation device configured to continuously generate a first atomic beam;
a second atomic beam generation device configured to continuously generate a second atomic beam;
a moving standing light wave generation device configured to produce M moving standing light waves each generated by a pair of counter-propagating laser beams, the M representing a predetermined integer satisfying 3≤M;
an interference device configured to make the first atomic beam and the second atomic beam going therein while traveling toward each other interfere with the M moving standing light waves to produce a third atomic beam and a fourth atomic beam, the third atomic beam resulting from interaction of the first atomic beam with the M moving standing light waves, and the fourth atomic beam resulting from interaction of the second atomic beam with the M moving standing light waves;
a first observation device configured to observe the third atomic beam; and
a second observation device configured to observe the fourth atomic beam,
wherein the M moving standing light waves are arranged in parallel to one another along a traveling direction of the first atomic beam, and arranged symmetrically with respect to a straight line orthogonal to the traveling direction of the first atomic beam, and
the moving standing light wave generation device adjusts two-photon detuning δ i of the pair of counter-propagating laser beams corresponding to an i-th moving standing light wave out of the M moving standing light waves and two-photon detuning δ M−i+1 of the pair of counter-propagating laser beams corresponding to an (M−i+1)-th moving standing light wave out of the M moving standing light waves such that a difference between an interferometric phase corresponding to the third atomic beam and an interferometric phase corresponding to the fourth atomic beam stays constant, the N representing a predetermined integer satisfying 2≤N<M, the i representing at least one integer among [M/2] integers satisfying 1≤N≤[M/2], the square bracket notation [ ] representing a floor function, and δ i =−δ M−i+1 being satisfied.
2 . The inertial sensor according to claim 1 , wherein
the moving standing light wave generation device adjusts two-photon detuning δ of the pair of counter-propagating laser beams corresponding to at least one of the M moving standing light waves except for the i-th moving standing light wave and the (M−i+1)-th moving standing light wave so as to keep constant an extremum of contrast of the population of the third atomic beam or an extremum of contrast of the population of the fourth atomic beam.
3 . The inertial sensor according to claim 2 , wherein
a distance between an M-th moving standing light wave out of the M moving standing light waves and the first observation device is equal to a distance between a first moving standing light wave out of the M moving standing light waves and the second observation device, and
a distribution of velocities of atoms in the first atomic beam in the traveling direction of the first atomic beam is the same as a distribution of velocities of atoms in the second atomic beam in the traveling direction of the second atomic beam.