Interband cascade laser amplifier medium

An interband cascade laser amplifier medium having a number of cascades strung together along a transport direction of charge carriers and each comprising an electron injector region, an amplifier region and an electron collector region, wherein:

• the amplifier region, comprises a hole quantum film comprising a first semiconductor material and an electron quantum film comprising a second semiconductor material;
• the electron collector region comprises at least one collector quantum film comprising a third semiconductor material and separated by a first barrier layer;
• the electron injector region comprises at least one injector quantum film comprising a fourth semiconductor material and separated by a second barrier layer;
• the optical laser transition takes place between (i) a conduction band of the electron quantum film and (ii) a valence band of the hole quantum film of the amplifier region:
• along the cascade and/or between two adjacent cascades in a conduction band and/or in a valence band, at least two subbands transport-coupled for charge carriers are formed in such a way that the succeeding subband in the transport direction, relative to the preceding subband in the transport direction, in the electric field of the operating case, is reduced energetically by an absolute value substantially equal to the energy of an optical phonon of the semiconductor materials involved;
• and
• wherein at least one of:
• (A) the preceding subband in the transport direction of the two subbands that differ energetically by an absolute value substantially equal to the energy of an optical phonon is formed in the valence band of the electron collector region and the succeeding subband in the transport direction is formed in the conduction band of the electron injector region:
• (B) the preceding subband in the transport direction of the two subbands that differ energetically by an absolute value substantially equal to the energy of an optical phonon is formed in the conduction band of the electron injector region and the succeeding subband in the transport direction is formed in the conduction band of the electron quantum film:
• and
• (C) the at least two subbands that differ energetically by an absolute value substantially equal to the energy of an optical phonon are formed in the conduction band of the electron injector region.