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DFB-Laser Diode has become a conventional product, and it is developing towards higher reliability and lower price. Lasing wavelength of DFB laser diode is mainly determined by the gate cycle of the micro-refraction light prepared inside the device. VCSEL (Vertical Cavity Surface Emitting Laser) diodes are as follows: Cylindrical beam is emitted from the top, and the beam can be modulated into annular beams without asymmetric or astigmatism, which is easy to couple with optical fibers.