The heterolaser

The heterojunction laser.



 

 

The heterolaser unlike traditional laser, made of a homogeneous material, has a ten times lower threshold current density and greater efficiency. For the generation of light requires a small value of the pump current.

 


The heterojunction laser:

The heterojunction laser is a semiconductor laserbased on heterostructures.

The first heterojunction laser created heterostructure GaAs – (Al, Ga)As in the USSR, Zh. I. Alferov with the staff in 1968.

The heterojunction laser based on heterostructures GaAs – (Al, Ga)As is a type of injection heterolaser.

It consists of several layers:

– the top layer – electrode in the form of a strip, to which is fed the negative charges (as electrons)

– mirror layer of GaAs,

– layer shell of AlхGa1-ha,

– the active layer of GaAs,

– layer shell of AlхGa1-ha,

– mirror substrate of GaAs,

– the bottom layer is the positive electrode.

GaAs is a semiconductor with high quantum yield of radiative recombination. Therefore, the active layer of GaAs is an active environment heterolaser. The active layer is of GaAs waveguide, the output of which is powerful, uniform and highly directional radiation. The spectrum of radiation of such a heterojunction laser is very narrow and mainly contains one fashion.

Shell layers made from AlхGa1-he have the energy of forbidden zone, which is higher than the energy of the forbidden zone of the active layer of GaAs. So the stimulated photons are held only in the active region and transferred to adjacent layers. Power radiation heterolaser with the one and same current of the pump is also larger than in the simplest laser. A refraction index of the active region of GaAs is greater than the neighboring heterocloeon shell of AlхGa1-ha, so the photons are fully reflected from the boundaries of the active zone.

The emission spectrum of the heterojunction laser based on heterostructures GaAs – (Al, Ga)As is equal to the width of forbidden zone of the active layer made of GaAs, and is the range from 0.4 µm to several tens of micrometers. The heterolasers can be used to generate the radiation power from a fraction of milliwatts to tens of watts.

The heterolaser unlike traditional laser, made of a homogeneous material, has a ten times lower threshold current density and greater efficiency. For the generation of light requires a small value of the pump current. The heterojunction laser can continuously generate light emission at room temperature.

 

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