Abstract: The invention describes a laser device comprising between two and six mesas (120) provided on one semiconductor chip (110), wherein the mesas (120) are electrically connected in parallel such that the mesas (120) are adapted to emit laser light if a defined threshold voltage is provided to the mesas (120). Two to six mesas (120) with reduced active diameter in comparison to a laser device with one mesa improve the yield and performance despite of the fact that two to six mesas need more area on the semiconductor chip thus increasing the total size of the semiconductor chip (110). The invention further describes a method of marking semiconductor chips (110). A functional layer of the semiconductor chip (110) is provided and structured in a way that a single semiconductor chip (110) can be uniquely identified by means of optical detection of the structured functional layer. The structured layer enables identification of small semiconductor chips (110) with a size below 200 ?m×200 ?m.

Abstract: The present invention relates to a laser device being formed of at least one VCSEL (15) with intracavity contacts. The VCSEL comprises a layer structure (18) with an active region (6) between a first DBR (4) and a second DBR (10), a first current-injection layer (5) of a first conductivity type between the first DBR (4) and the active region (6), and a second current-injection layer (8) of a second conductivity type between the second DBR (10) and the active region (6). The first and second current-injection layers (5, 8) are in contact with a first and a second metallic contact (11, 12), respectively. The first and/or second DBR (4, 10) are formed of alternating Aluminum oxide and Al(x)Ga(1?x)As containing layers. The proposed design of this VCSEL allows an increased efficiency and lower production costs of such a laser since the top and bottom DBRs may be formed of a considerable reduced thickness.

Abstract: The present invention relates to a VCSEL array comprising several VCSELs arranged side by side on a common substrate (1). Each VCSEL is formed of at least a top mirror (5, 14), an active region (4), a current injection layer (3) and an undoped bottom semiconductor mirror (2). The current injection layer (3) is arranged between the active region (4) and the bottom semiconductor mirror (2). At least an upper layer of the substrate (1) is electrically conducting. Trenches (8) and/or holes are formed between the bottom semiconductor mirrors (2) of said VCSELs to said upper layer of said substrate (1). A metallization (9) electrically connects the upper layer of the substrate (1) with the current injection layer (3) through said trenches (8) and/or holes. The proposed VCSEL array allows a homogeneous current injection an has a high efficiency and power density.

Abstract: The present invention relates to a VCSEL array comprising several VCSELs arranged side by side on a common substrate (1). Each VCSEL is formed of at least a top mirror (5, 14), an active region (4), a current injection layer (3) and an undoped bottom semiconductor mirror (2). The current injection layer (3) is arranged between the active region (4) and the bottom semiconductor mirror (2). At least an upper layer of the substrate (1) is electrically conducting. Trenches (8) and/or holes are formed between the bottom semiconductor mirrors (2) of said VCSELs to said upper layer of said substrate (1). A metallization (9) electrically connects the upper layer of the substrate (1) with the current injection layer (3) through said trenches (8) and/or holes. The proposed VCSEL array allows a homogeneous current injection an has a high efficiency and power density.

Abstract: It is an object of the invention to simplify the power stabilization of laser diodes. For this purpose, a laser device comprising a die and thereon a first laser diode and a second laser diode is provided. The second laser diode has a structure or element that avoids lasing if a supply voltage is applied that is sufficient for the first semiconductor laser cavity to emit laser light.

Abstract: The present invention relates to a vertical cavity surface emitting laser device comprising a VCSEL with a monolithically integrated photodiode. The photodiode (2) is formed of a layer sequence of a first n-doped region (6), a p-doped region (7), an intrinsic region (8) and a second n-doped region (9) of a semiconductor material. The photodiode (2) and the laser share a common electrode, which is realized as an Ohmic n-contact (10) at said first n-doped region (6). The proposed device allows less complex manufacturing, resulting in lower manufacturing costs.

Abstract: It is an object of the present invention to improve the confinement of the carriers within a VCSEL. As a general concept of the invention, it is proposed to integrate a phototransistor layer structure into the layer stack of the VCSEL.

Abstract: It is an object of the present invention to improve the confinement of the carriers within a VCSEL. As a general concept of the invention, it is proposed to integrate a phototransistor layer structure into the layer stack of the VCSEL.

Abstract: It is an object of the invention to simplify the power stabilization of laser diodes. For this purpose, a laser device comprising a die and thereon a first laser diode and a second laser diode is provided. The second laser diode has a structure or element that avoids lasing if a supply voltage is applied that is sufficient for the first semiconductor laser cavity to emit laser light.

Abstract: The present invention relates to a vertical cavity surface emitting laser device comprising a VCSEL with a monolithically integrated photodiode. The photodiode (2) is formed of a layer sequence of a first n-doped region (6), a p-doped region (7), an intrinsic region (8) and a second n-doped region (9) of a semiconductor material. The photodiode (2) and the laser share a common electrode, which is realized as an Ohmic n-contact (10) at said first n-doped region (6). The proposed device allows less complex manufacturing, resulting in lower manufacturing costs.