  Long ground-Rydberg coherence lifetime is interesting for implementing
high-fidelity quantum logic gates, many-body physics, and other quantum
information protocols. However, the potential well formed by a conventional
far-off-resonance red-detuned optical-dipole trap that is attractive for
ground-state cold atoms is usually repulsive for Rydberg atoms, which will
result in the rapid loss of atoms and low repetition rate of the experimental
sequence. Moreover, the coherence time will be sharply shortened due to the
residual thermal motion of cold atoms. These issues can be addressed by a
one-dimensional magic lattice trap, which can form a deeper potential trap than
the traveling wave optical dipole trap when the output power is limited. In
addition, these common techniques for atomic confinement generally have certain
requirements for the polarization and intensity stability of the laser. Here,
we demonstrated a method to suppress both the polarization drift and power
fluctuation only based on the phase management of the Mach-Zehnder
interferometer for a one-dimensional magic lattice trap. With the combination
of three wave plates and the interferometer, we used the instrument to collect
data in the time domain, analyzed the fluctuation of laser intensity, and
calculated the noise power spectral density. We found that the total intensity
fluctuation comprising laser power fluctuation and polarization drift was
significantly suppressed, and the noise power spectral density after
closed-loop locking with a typical bandwidth of 1-3000 Hz was significantly
lower than that under the free running of the laser system. Typically, at 1000
Hz, the noise power spectral density after locking was about 10 dB lower than
that under the free running of a master oscillator power amplifier system.The
intensity-polarization control technique provides potential applications.
