The 355nm Nd：YAG laser has the advantages of good beam quality, stable power, high reliability, small size,and is easy to use, suitable for industrialization. It has been widely used in laser processing in bioengineering, material preparation, all-optical optics, integrated circuit boards and semiconductor industries.
The main components of device are:
The Q-switching method adopts electro-optic Q-switching. Through accurate control of the external voltage, the phase difference of the fast and slow light after passing through the crystal can be realized, which can change the polarization direction of the output light. The chosen Q switch crystal is Cr YAG crystal, whose applied range is 900 – 1200 nm and 1350 – 1600 nm and the damage threshold is above 500 MW/cm2.
The LBO crystal was selected for intracavity mixing to produce the desired 355 nm UV laser. The two LBO crystals are cut according to the phase matching angles of I and II respectively. The crystal end faces are plated with three-color antireflection coatings of 1064 nm, 532 nm and 355 nm, and the crystal placement meets the polarization matching conditions.
M1——a concave mirror plated with a full-reflection film for a wavelength of 1064 nm. M2——Planar tri-color mirror, 45° reflection to the fundamental wave, 45° increase permeability on both sides to532nm and 355nm light wave. M3——output mirror. The fundamental wave and the frequency-doubled light are all reflected, and the sum frequency is increased permeability. M4——flat concave mirror. Fully reflect for 532nm and 355nm.
Ultraviolet lasers have three advantages in laser processing: First, they can process very small parts with a short wavelength. Second, ultraviolet laser processing materials directly destroy the chemical bond of the material, is a “cold” process, the heat affected area is small. Third, most materials can effectively absorb ultraviolet light.
- Good beam quality
- Power stability
- High reliability
- Ultraviolet light can be absorbed more effectively
- Cold process
- Biological Engineering
In the process of manufacturing a microfluidic chip by ultraviolet laser, the chemical bond in the molecule is directly cut, and the material is decomposed and removed. There is no need for a mask during laser direct writing to make a microfluidic chip. The entire production process is flexible and fast.
- Laser welding
The diffraction grating can be prepared by ultraviolet laser ablation. The computer control laser beam to write stripe structure of the grating on the surface of the material. The film in the writing area is ablated, and the substrate is exposed to form a grating structure on the surface of the material. The operation is simple, convenient and fast.
- Laser Hole Drilling
The application of UV laser on the circuit board is mainly to drill fine holes, cut flexible circuits, and manufacture and repair integrated circuit boards on polymer and copper layer distributed circuit boards. The UV laser can be used for holes below 25mm with high precision. Ultraviolet lasers can perforate, cut and weld on a variety of materials.