In semiconductor lasers’ family, mid-IR or far-IR lasers(830nm/1064nm)are both important parts, but there is another import member absent – short wavelength(visible light) lasers, namely blue and green lasers. 
In 2004, independently developed GaN-based laser diodes(blue LDs) have been achieved successfully, now it’s on the way from research to application.

LDs applications：

blue LDs(405nm  <400—415nm>) can be used for high-density data storage, laser print, laser display, laser projection camera, etc. 

Future： 

GaN-based MQWs LDs
Short wavelength laser: Green/UV/Deep UV