2600 W High Efficiency Laser Diode Source with Polarization Coupling

As the increasing applications of laser diodes in laser cladding and laser hardening,the single laser diode optical power can not meet the actual requirements.An improvement of the power and power density is necesary and it can be achieved by beam shaping and beam combination such as polarization coupling.The polarization coupling technology is used to couple two laser beams with thin-film plate polarizer.In this paper,two 808 nm vertically stacked arrays with an output power of 1 500 W was achieved.After fast axis and slow axis collimated,the polarization direction of one stacked arrays is rotated 90° through a half wave plate,thus,the polarization directions of two laser stack are vertical.The beams of two lasers are incident on thin-film plate polarizer;one transmits through it,and the other is reflected on it.Finally,two beams combine to one.Polarization coupling of two bars increases the power by a factor of 1.6,and the output power is 2 600 W,electro-optical conversion efficiency is more than 48%.The spot size is about 1 mm ×2 mm.This source reaches an intensity of 130 kW·cm-2.This laser can be directly applied to cladding,surface hardening and other fields.