Introduction to Semiconductor Laser

Semiconductor laser have the advantages of compact structure, high electro-optical conversion efficiency, and wide lasing wavelength range, and have a wide range of applications in optical communication, laser processing, laser ranging, and biomedical equipment. The tapered semiconductor laser amplifier can amplify the power of the single-mode seed light source, and the output power is high without affecting the beam quality. There are mainly two methods: external cavity injection and monolithic integration. External cavity structure means that the light source is emitted from an external cavity semiconductor laser (External Cavity Diode Lasers, ECDL), and then imported into a tapered amplifier chip for amplification, but this structure has disadvantages such as large volume, complex structure, and need for gain matching. Among them, the tapered semiconductor laser with monolithic integrated main oscillator is a promising high beam quality laser light source structure. With the improvement of the application level of semiconductor lasers, the research of tapered semiconductor lasers has been paid more and more attention.