355 nm UV DPSS

The 355nm DPSS laser is popular now, it's one kind of cold laser for laser cutting or marking. It doesn't like traditional high power DPSS laser, the 355nm laser doesn't damage the surfaces.

Here is the 355 nm UV laser beam splitting principle

UV-Grade Fused Silica Prism are used in 355nm UV laser.

Flatness: λ/5
Surface Quality: Class I
Clear Aperture:18mm × 10mm
Transmission: R>99.5%, λ=266-355nm, Brewster angle of incidence
Coating: Without coating
Angle of incidence: 57+/-1°

Here is BeamQ 355 nm UV DPSS laser, it's the newest products with reasonable price. BeamQ 355nm lasers are developed in China, therefore it's the best low cost 355nm in the world. The price is only 1/3 to the similar products in the market. 

There are different 355nm laser system, you need to choose the right one according to your needs. It's a list for you to purchase 355nm laser.

Laser Solid-State Quasi-CW 355 nm Xcyte. The JDSU Xcyte series lasers offer the advantages of diode-pumped solid-state lasers in quasi-CW 355nm air-cooled format. JDSU Xcyte CY-SM60-M1 355nm 60mW Laser System at eBay , the seller name is junktronix .

Model Garnet 355nm (Divergence 3.0mrad,Repetition rate 200-2000Hz) from laser-export, It is research, development and manufacturing of ultra-violet, green and infrared DPSS lasers.

Coherent Avia 355nm Solid State Q-switched ultraviolet lasers. It outputs 10W 355nm at 60kHz with excellent beam quality.The Daytona HE UV fiber laser provides output at 355 nm in nanosecond and shorter pulses with peak powers of >45 kW (at repetition rates up to 525 kHz) and high pulse energies of >70 microJ (at up to 325 kHz repetition rate). With is TEM00 mode quality (M2 <1.3), uses include precision micromachining of semiconductors, glasses, organics, metals, and other materials.

Passively Q-switched UV, Actively Q-switched UV and CW UV 355nm laser from optoengine, Near TEM00 beam and Single pulse energy 0.1uJ~60uJ.

Diode End-Pumped 1064nm / 532nm / 355nm / 266nm Nd:YVO4 Q-Switched Laser nanosecond for $7000 at alliedscientificpro.

Here are more 355nm laser sellers

Here are some 355nm UV laser system for micro material processing:

LPKF ProtoLaser U3: The LPKF ProtoLaser U3 creates applications that were previously only possible using a large industrial system. The integrated UV laser can process a variety of materials, including laminated substrates.

Some customer reviews about U3:

1. I used an LPKF system back when all they had were rotaries... the PC boards took a few hours to create, but they were immensely useful for fast-turnaround prototyping. Making a couple of PCBs in a single day rather than killing off most of a week waiting for the board house to get you something was awesome.The cheaper UV systems operate similar to the hobbyist UV light exposure systems with acetate sheets ran through the laser printer... but since you're skipping a few steps, it's much faster. PCBs are coated with a photopolymer, hardened with the UV laser like an inkjet printer/plotter, then etched. I believe LPKF's system does a direct etch of the copper on the board, as well as providing tooling for drilling holes.

2. I've used them, very nice bit of kits to have, cold marking, able to do many substrates that a infrared just wont touch, the lasers can be a bit delicate as the non-linear crystals in them wear out over time, 

More information about 355nm laser:

Low cost of 355nm solid state laser for material processing applications

Get a simple guide about 355nm laser at 355nm laser information

220W output power at 355nm from a Q-switched DPSS laser.

High Efficient LD End-pumped QCW 355 nm Laser: A LD end pumped acousto-optic Q-switched Nd:YVO4 solid state 355 nm ultraviolet laser is reported by using intra-cavity double frequency and extra-cavity sum frequency technique. Nd:YVO4 crystal bonded by YVO4 in its both sides is end-pumped by LD, and typeⅠphase matched LiB3O5 (LBO) as the second harmonic generation crystal is placed in the cavity. 1 064 nm and 532 nm dual wavelength output from the cavity are coupled into the typeⅡ phase matched LBO crystal through an achromatic lens. High efficiency, good beam quality and high repetition rate 355 nm ultraviolet laser is obtained by sum frequency mixing back and forth. 

High-volume manufacturers looking to meet miniaturization challenges while reducing costs can use the single-mode fiber marker to achieve excellent results on a range of materials, including steel, nickel, titanium, silicon, aluminum, and copper. The method should be considered by those thinking about updating or replacing electric discharge machining (EDM) equipment, as well as those who might otherwise turn to 532nm and 355nm lasers.

Cobolt Zouk 355nm laser is a continuous wave DPSS  laser. It is a single-frequency laser with high level of stability, ultra-low noise, very narrow spectral bandwidth and a perfect quality beam over a wide range of operation temperatures. They have these available wavelengths on the same platform: 355nm, 491nm, 532nm, 561nm, 660nm, 1064nm . Cobolt supplies DPSSLs  and Diode Laser Modules in the visible, invisible and near infrared spectral ranges. It's a lasr company from Sweden . They have sales offices in USA, Europe.

ALPHALAS GmbH is a German laser manufacturer. They are offering a wide range of products in the fields of lasers, optics and laser-related electronics. Advanced DPSS Lasers made in Germany, from UV to IR and from CW to fs:Modelocked DPSSL (100 fs - 100 ps),Q-Switched DPSSL. Nd:YAG 1064 nm, 532 nm, 355 nm, 266 nm.

AMS Technologies has announced the PUFL UV fiber 355nm lasers. Combinating of a 1.0-µm fiber laser and a compact frequency converter, it keeps the converter at a constant temperature. Energy per pulse can reach up to 2 µJ with peak power at 2 kW and a 50-kHz pulse repetition frequency. The output beam is collimated and near-Gaussian, with M2<1.3.