Semiconductor diode laser device

Claim 2

A semiconductor diode laser device comprising: a semiconductor body having a pair of opposed reflecting surfaces forming a laser resonator; a first pn junction formed within the laser resonator and having a major plane portion extending in a plane perpendicular to said reflecting surfaces; a second pn junction formed within the laser resonator and spaced apart from said first pn junction, said second pn junction having a plane portion substantially coplanar to the major plane portion of said first pn junction; means for applying to said first pn junction a forward bias voltage having a predetermined value sufficient to cause the semiconductor body in the vicinity of said first pn junction to generate a stimulated emission light beam so that the stimulated emission light beam is generated and advanced in a direction parallel to said first pn junction; and means for supplying a variable reverse voltage to said second pn junction so as to establish a variable depletion layer in said semiconductor body in the neighborhood of said second pn junction, the variable depletion layer being positioned in the light path of said stimulated emission light beam between said reflecting surfaces and having a light attenuating property, so that the stimulated emission light beam repeatedly reflected by the reflecting surfaces is attenuated to thereby modulate the resulting laser beam emitted from one of the reflecting surfaces of the laser resonator in accordance with the variable reverse voltage.

Claim 3

A semiconductor diode laser device comprising: a semiconductor body of one conductivity type having a pair of opposed reflecting surfaces forming a laser resonator; two semiconductor regions of another conductivity type opposite to said one conductivity type formed on a surface of said semiconductor body spaced apart from each other so as to form a first and a second pn junction therebetween, respectively, the first pn junction being formed within said laser resonator and having a major plane portion extending in a plane perpendicular to said reflecting surfaces and the second pn junction being formed within said laser resonator and disposed apart from the first pn junction and having a plane portion extending in the same plane as the major plane portion of the first pn junction; means for supplying a variable reverse voltage to said second pn junction to establish a variable depletion layer along said second pn junction, said depletion layer operatively attenuating light beams passing therethrough; and means for supplying a forward bias voltage of a predetermined value to said first pn junction to generate a stimulated emission light beam, said light beam being advanced along the major plane portion of the first pn junction said repeatedly reflected between said reflecting surfaces under the combined stimulation of said first pn junction and modulation of said depletion layer, to thereby emit from one of said reflecting surfaces a laser beam modulated in accordance with the variable reverse voltage applied across said second pn junction.

Claim 4

A semiconductor diode laser device comprising: a semiconductor body of one conductivity type having a pair of opposed reflecting surfaces forming a laser resonator; two semiconductor regions of another conductivity type opposite to said one conductivity type formed on a surface of said semiconductor body spaced apart from each other so as to form a first and a second pn junction therebetween, respectively, the first pn junction being formed within said laser resonator and having a major plane portion extending in a plane perpendicular to said reflecting surfaces and the second pn junction being formed within said laser resonator and disposed apart from the first pn junction and having a plane portion extending in the same plane as the major plane portion of the first pn junction; means for supplying a variable reverse voltage to said second pn junction to establish a variable depletion layer along said second pn junction, said depletion layer operatively attenuating light beams passing therethrough; and means for supplying a forward bias voltage of a predetermined value to said first pn junction to generate a stimulated emission light beam, said light beam being advanced along the major plane portion of the first pn junction said repeatedly reflected between said reflecting surfaces under the combined stimulation of said first pn junction and modulation of said depletion layer, to thereby emit from one of said reflecting surfaces a laser beam modulated in accordance with the variable reverse voltage applied across said second pn junction.

Claim 5

A semiconductor diode laser device according to claim 1, wherein said first pn junction is formed in the semiconductor body in substantially an elongated shape extending between the reflecting surfaces over a distance less than the spacing between the reflecting surfaces.

Claim 6

A semiconductor diode laser device according to claim 11, wherein said semiconductor body is substantially elongated in one direction and wherein said reflecting surfaces are disposed at the longitudinal ends of the longitudinally elongated semiconductor body, said first and second pn junctions having plane portions which are coplanar and spaced from each otHer in the longitudinal direction in the semiconductor body, the plane portion of said first pn junction being formed in the semiconductor body as an elongated longitudinally extending junction part, and the plane portion of said second pn junction being at least in part thereof disposed between said first pn junction and one of said reflecting surfaces.

Claim 7

A semiconductor diode laser device according to claim 4, wherein said second pn junction includes a first portion of relatively small width disposed between said first pn junction and one of said reflecting surfaces and a second portion of relatively larger width than said first portion disposed in parallel to and longitudinally extending along said first pn junction, said first and second portions of the second pn junction establishing a first depletion layer having a light attenuating action in the path of a laser beam advancing in the longitudinal direction of said first pn junction and a second depletion layer having a sufficient light suppressing action in the path of the stimulated emission light beam advancing in directions other than said longitudinal direction of said first pn junction, respectively, and wherein said means for supplying a variable reverse voltage is adjustable to vary the attenuation property of the first depletion layer in accordance with the reverse voltage and to provide the second depletion layer with sufficient light suppressing action to sufficiently suppress light beams advancing in directions other than the longitudinal direction of said first pn junction to thereby provide a modulated laser beam advancing in the longitudinal direction of said first pn junction from the laser resonator, the intensity of which is modulated in accordance with the variation in the variable reverse voltage.

Claim 8

A semiconductor diode laser device according to claim 5, wherein said second pn junction is substantially in the form of an L and wherein said second portion of said second pn junction extends longitudinally along one of the longitudinally elongated sides of said first pn junction whereas said first portion of said second pn junction extends transversely along one of the longitudinal ends of said first pn junction.

Claim 9

A semiconductor diode laser device according to claim 5, wherein said second portion of said second pn junction extends longitudinally along both elongated sides of said first pn junction.

Claim 10

A semiconductor diode laser device according to claim 1, wherein said semiconductor body comprises a first conductivity type semiconductor material, said first pn junction is formed between said semiconductor body and a first diffused region of a second conductivity type opposite to said first conductivity type, and said second pn junction is formed between said semiconductor body and a second diffused region of said second conductivity type spaced apart from said first diffused region.