Fig. 1. Diagram of energy level and transition for atomic Rb DPAL

Fig. 2. Pumped diode laser used in DPAL by LLNL

Fig. 3. Model of pumped laser for DPAL^[29]

Fig. 4. Architecture for DPAL power scaling^[35]

Fig. 5. Window damage in alkali cells in different flowing field and buffer gases^[31]. (a) Window damage in Cs alkali cells filled with static methane buffer gas; (b) window damage in Cs alkali cells filled with flowing methane buffer gas; (c) window damage in K alkali cells filled with flowing He buffer gas

Fig. 6. Design of transversely pumped Cs laser with stable resonator and unstable resonator^[26]. (a) Stable resonator; (b) unstable resonator

Table 1. Comparison of characteristic of D line for different alkali atoms

Table 2. Main achievement on concept research of DPAL in the beginning

Table 3. Achievement on power of DPAL during fast improving period

Table 4. MW DPAL main design parameters^{and evaluation of TRL}