Display method of converting infrared laser path into visible light

The present invention belongs to the field of laser machining technology, and is especially one display method of converting infrared laser beam into visible light. One kind of up-converting RE doped crystal is grown in proper growth process, and after annealing, orientating, cutting and surface polishing, the up-converting RE doped crystal is set on operating platform to convert infrared laser beam of 0.8-1.06 micron wavelength into blue beam with one narrowest part to define the position of the focus. The method of the present invention is superior to available inclined plate method and vertically elevating method, and has the advantages of being intuitive, efficiency, reliable and economic. The method may be used in infrared path display and focus measurement as well as laser medicine and other fields needing precise observation of laser beam path and precise determination of laser focus.