what is 355nm UV Solid State Laser: 

355nm Ultra Violet UV DPSS laser is a new laser technology, widely used in laser cutting and engraving.355nm laser is used in university experiments, however the highest continuous power is < 20mW. If you need higher power, the pulses 355nm UV laser can reach 1000mW (1W). Most of the users install 355nm DPSS laser into engraving machines.

There are four types :

CW ultraviolet laser at 355 nm,

Passively Q-switched ultraviolet laser at 355 nm,

Actively Q-switched ultraviolet laser at 355 nm,

Fiber coupled laser system at 355 nm

what is  ultraviolet laser 355 nm: https://www.rfhtech.com/s9-y-integrated-uv-laser_c4