Leaky wave diode laser

An electrically pumped heterojunction diode laser comprising:

• a solid state body including a plurality of contiguous layers,
• one of said layers being and active region layer formed of a semiconductor material,
• a carrier confinement layer on at least one side of said active region layer, said confinement layer being of a semiconductor material having an index of refraction lower than the index of refraction of the semiconductor material of said active region layer whereby a heterojunction is provided within said body,
• an additional layer of semiconductor material on the side of said confinement layer remote from said active region layer, the material of said additional layer having a higher refractive index than the material of said confinement layer, said additional layer being substantially thicker than both said confinement layer and said active region layer,
• a rectifying junction within said semiconductor body, and
• means for biasing said rectifying junction to provide for carrier injection across said rectifying junction with carrier recombination in said active region layer providing for the generation of radiation of a given wavelength and mode pattern,
• said confinement layer being sufficiently thin so that a portion of said mode pattern of said generated radiation extends into said additional layer to provide an unguided leaky wave in said additional layer, said leaky wave making an angle to said heterojunction and being emitted from said body at an angle to said heterojunction,
• the absorption coefficient of said additional layer being such that said leaky wave portion of said mode pattern is not attenuated substantially by said additional layer.

An electrically pumped heterojunction diode laser comprising:

• a solid state body including a plurality of contiguous layers,
• one of said layers being an active region layer formed of a semiconductor material,
• a carrier confinement layer on at least one side of said active region layer, said confinement layer being of a semiconductor material having an index of refraction lower than the index of refraction of the semiconductor material of said active region layer whereby a heterojunction is provided within said body,
• an additional layer of semiconductor material on the side of said confinement layer remote from said active region layer, the material of said additional layer having a higher refractive index than the material of said confinement layer, at least a portion of said confinement layer being substantially thinner than said additional layer.
• a rectifying junction within said semiconductor body, and
• means for biasing said rectifying junction to provide for carrier injection across said rectifying junction with carrier recombination in said active region layer providing for the generation of radiation of a given wavelength and mode pattern,
• said portion of said confinement layer being sufficiently thin so that a portion of said mode pattern of said generated radiation extends into said additional layer to provide an unguided leaky wave in said additional layer, said leaky wave making an angle to said heterojunction and being emitted from said body at an angle to said heterojunction,
• the absorption coefficient of said additional layer being such that said leaky wave portion of said mode pattern is not attenuated substantially by said additional layer.