Fig. 1. Schematic diagram of reflective type structure

Fig. 2. Selecting appropriate crystal orientation to produce 45° mirror

Fig. 3. Single-step process for atomic cell. (a) Wet etching of Si; (b) etching angle of 45°; (c) microscopic distribution of alkali metals in MEMS gas chamber;

Fig. 4. Overall process flow of alkali metal MEMS vapor chamber. (a) Preparation of Si; (b) wet etching; (c) deposition of aluminum; (d) first anodic bonding; (e) pipetting and drying; (f) evaperation; (g) second anodic bounding

Fig. 5. Schematic diagram of circuit structure for measuring frequency stability and internal diagram of physical system. (a) Schematic diagram of circuit structure; (b) internal diagram of physical system

Fig. 6. Alkali metal MEMS vapor chamber test. (a) Atomic vapor cell containing 6 mm optical length cavity; (b) test fixture for testing alkali metal atomic vapor cell; (c) frequency stability of MEMS vapor cell