## 1 Introduction  
The physical implementation of a single-photon source has important application value in the fundamental research of quantum optics and linear quantum computation, especially the controllable triggered single-photon source as its core quantum source. Generally, one can generate single-photons via single-atom, single-molecule, single-ion, single-quantum dots or parametric down-conversion. Compared with the said ways, single-atoms have advantages of narrowband, matching atom transition lines and weak coupling of neutral ground-state atoms with background light and external electromagnetic fields. Single-atom source based on the captured single-atom in an optical tweezer [1, 2, 3] paves the way for quantum repeaters, quantum teleportation, quantum secure communications and linear quantum computing. In 1975, [PERSON] and [PERSON] first put forward the use of the laser to cool neutral atoms [4]. In 1987, the research group led by [PERSON] cooled and captured neutral Sodium atoms with magneto-optical trap (MOT) for the first time [5]. In 1994, [PERSON]'s team first achieved the cooling and capture of a single-atom [6]. In 2016, the [PERSON] group constructed a two-dimensional atom array composed of 50 single-atoms trapped in optical tweezers [7]. In 2018, [PERSON] group constructed a three-dimensional atom array composed of 72 single-atoms trapped in optical tweezers, optionally manipulating the spatial position of each atom [8]. In our system, we have already captured [2; 9] and transferred [10; 11] single-atoms to optical tweezer efficiently, built cesium (Cs) magic-wavelength optical dipole trap [2; 3], and finally achieved triggered single-photon source at 852 nm based on single-atom manipulation [3; 12].  
When manipulating the single-atoms in the optical tweezers, it is required that the atoms be captured. We must capture all the atoms in the tweezers before finishing all the operations. Therefore, it is important to prolong the trapping lifetime of atoms in the optical tweezer, to improve the experimental efficiency and the experimental accuracy.  
The trapping lifetime of an atom in the optical tweezer is limited by many factors such as recoil heating, laser intensity fluctuation, the degree of atomic vapor, laser beam pointing stability and the residual atom thermal motion. One can suppress the laser intensity fluctuation [13], increase background vacuum degree, improve the laser pointing stability, increase the laser power and adopt the polarization gradient cooling [14] to prolong the trapping lifetime of a single-atom in the optical tweezer. In this work, we discussed the influence of the vacuum degree and the light intensity fluctuation of 1064-nm optical tweezer on atom trapping lifetime and the experimental methods of improving the fluctuation of the laser intensity.  
Generally, one can suppress the laser intensity fluctuation with optical mode cleaner [15], optical inject lock [16] or acousto-optical modulator (AOM) feedback [13; 17]. Thanks to its flexibility and simplified experimental setup, the AOM feedback becomes the best candidate to suppress the laser intensity fluctuation only by controlling the diffraction efficiency of AOM.