July 25
Siberian scientists are developing lasers in the green spectrum
Employees of the Institute of Semiconductor Physics SB RAS and Molecular Photonics Laboratory NSU are involved in one of the most important directions in today's laser technology — the creation of green LEDs and laser diodes (scientists from Japan and the United States won the Nobel Prize in 2014 for creating the blue LEDs).
Siberian scientists are developing LEDs and solid-state laser diodes based on the effect of green luminescence in optical transitions through levels of crystal lattice defects in the layers of aluminum gallium nitride (AlGaN), heavily doped with donors.
There are many ways how we can use green lasers: they can be used in land-based and underwater locators, range finders, aircraft landing systems and ship escorting, guidance devices and topographic sight, speed interferometry and photographs, projection television, live cell diagnostic equipment, etc...
From the identified effect it is possible to create ultra-fast laser pulses with a duration of light about 10-15 seconds.
At the moment, Novosibirsk scientists are performing measurements of the active medium gain (a very important parameter for the laser). The first results provide a sufficiently large value of this parameter on the point about 70 cm-1, which gives researchers optimism. Also, the scientists are working on clarifying the nature of the defects, which gives green luminescence.
Finally, the prototype production of green LEDs based on the AlGaN is going to be completed soon. It should demonstrate the effectiveness of using this alternative material for light-emitting devices.