Frequency tripling device for ultrafast laser and method of the same

Abstract

The invention discloses a frequency tripling device for an ultrafast laser and a method of the same. An output optical path of an ultrafast infrared laser is provided with frequency doubling crystals and frequency tripling crystals in sequence. The output end surface of the frequency tripling crystal is an output end surface of the cut at Brewster angle, wherein an output optical path of an infrared light and an output optical path of a green light are provided with light barriers, and an output optical path of an ultraviolet light is provided with a wedge lens. After an infrared laser light is output by the ultrafast infrared laser and passes through the frequency doubling crystal, part of the infrared light is converted to the green light, and the ultraviolet light is produced when the remaining infrared light and green light pass through the frequency tripling crystal. Lights of three wavelengths are respectively transmitted in different directions after passing through the output end surface of the cut at Brewster angle of the frequency tripling crystal. The infrared light and the green light are respectively blocked by two light barriers. A round light spot of the ultraviolet light which is produced inside the frequency tripling crystal changes into an oval light spot after the ultraviolet light passes through the frequency tripling crystal. The oval light spot changes into a round light spot again after the shaping of the wedge lens. Provided with the frequency tripling end surface and uncoated lens, the frequency tripling device for the ultrafast laser has the advantages that the service life is greatly prolonged.

Description

technical field [0001] The invention relates to an ultrafast laser triple frequency device and a method thereof. Background technique [0002] Ultrafast lasers (picoseconds, femtoseconds) have been widely used in the fields of fine microprocessing of materials, semiconductor industry, solar photovoltaics, scientific research and other fields due to their high peak power and narrow pulse width. Compared with nanosecond laser, the use of ultrafast laser to process materials has the advantages of high precision, small heat-affected area, and no burr on the processing edge. Ultrafast lasers are divided into ultrafast infrared, green and ultraviolet lasers according to their wavelengths. Compared with ultrafast infrared and green lasers, ultrafast ultraviolet lasers have higher photon energy, which acts on materials to directly destroy molecular bonds of materials, effectively reducing or eliminating the thermal effect caused by laser processing. At the same time, because the u...

AI Technical Summary

Problems solved by technology

The frequency tripler crystal used for ultrafast lasers is usually a cuboid. The input end is coated with infrared and green anti-reflection coatings, and the output end is coated with infrared, green and ultraviolet three-wavelength anti-reflection coatings. The energy of laser photons is high, and it is very easy to damage the film layer at the output end, resulting in a decrease in output power and deterioration of beam quality

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