We study the effect of losses on the phase sensitivity of the SU(1,1) interferometer for different configurations. We find that this type of interferometer is robust against losses that result from an inefficient detection system. This type of loss only introduces an overall prefactor to the sensitivity but does not change the 1/n scaling characteristic of the Heisenberg limit. In addition, we show that under some conditions the SU(1,1) interferometer with coherent state inputs is also robust against internal losses. These results shows that the SU(1,1) interferometer is a viable candidate for experimentally reaching the Heisenberg limit with current technology. Possible implementations of the interferometer using four-wave mixing in atomic vapors and an atom interferometer in a Bose-Einstein condensate are compared and certain advantages of the atom interferometer are discussed.
Physical Review A
Non-linear optics, parameter estimation, precision measurements