A Vertical-Cavity Surface-Emitting Laser (VCSEL) is a kind of semiconductor laser, whose laser is emitted perpendicular to the top surface. Developed on the basis of gallium arsenide semiconductor material, it is different from LED (Light Emitting Diode) and LD (Laser Diode). It consists of a mirror surface, an active layer and a metal contact layer. The two transmitting mirrors are P-type and N-type Bragg transmitters. The active region is composed of quantum hydrazine. A metal contact layer is made on the outer surface of the P-type DBR to form ohmic contact, and a circular outlet is made on the P-type DBR to output laser. It has a small far-field divergence angle, and the divergence angle beam is narrow and round. And the threshold current is low and the modulation frequency is high, which can reach 300KHz. The wavelength tuning can be realized by changing the laser current and temperature. Package with TEC and PD inside, which is specially designed for high-speed optical fiber communication.