The laser diode is essentially a semiconductor diode. According to whether the PN junction material is the same, the laser diode can be divided into a homojunction, a single heterojunction (SH), a double heterojunction (DH) and a quantum well (QW) laser diode. Quantum well laser diodes have the advantages of low threshold current and high output power, and are the mainstream products in the market. Compared with lasers, laser diodes have the advantages of high efficiency, small size and long life.
