Fig. 1. Theoretical simulation：（a）the relationship between the thickness and composition of quantum wells when the gain peak wavelength is at 750 nm and 760 nm，（b）the gain spectrum of AlGaAs quantum wells with different thicknesses when the gain peak is at 750 nm

Fig. 2. （a）The relationship between the gain of the light-emitting region material with different quantum well thicknesses and the carrier concentrations，（b）the gain spectrum of the 4 nm AlGaAs quantum wells under different carrier concentrations

Fig. 3. （a）The quantum well gain spectrum of the light-emitting region at different temperatures simulated theoretically，（b）the reflection spectrum of the VCSEL laser at different temperatures，（c）the relationship between the cavity mode wavelength and the gain peak wavelength of the VCSEL laser as a function of the operating temperature curve

Fig. 4. The schematic diagram of the VCSEL laser structure

Fig. 5. The VCSEL preparation process

Fig. 6. P-I-V characteristic curves of the VCSEL lasers at different operating temperatures，the inset shows an infrared microscope photograph of the oxidation pore and a VCSEL laser spectrum at 25 °C，4 mA operating current

Fig. 7. The test results of the laser divergence angle of the VCSEL laser under different working currents，the inset is the far-field spot when the working current is 4 mA

Fig. 8. （a）The variation of the VCSEL laser wavelength with the operating current when the operating temperature is 15 °C，25 °C and 35 °C，（b）the variation of the VCSEL laser wavelength with the operating temperature when the operating current is 1.4 mA，2.5 mA，3 mA and 3.5 mA

Fig. 9. （a）The laser spectrum when working temperature is 25 °C and working current is 1.8 mA，（b）the laser spectrum when working temperature is 35 °C and working current is 4 mA

Fig. 10. The SMSR at different currents when working temperature is 35 °C