Semiconductor laser device with a strain reduction cushion function, semiconductor laser module, and semiconductor laser device fabrication method

A semiconductor laser device comprising:

• a semiconductor laser element comprising an active layer disposed between first and second electrodes that inject a current into an active layer;
• a first metallic thin film layer provided on a surface of the second electrode;
• a submount having electric insulating and high thermal conductivity properties, said submount having a second metallic thin film layer provided on a surface of the submount;
• and
• a solder layer configured to connect the first metallic thin film layer to the second metallic thin film layer,
• wherein the second electrode, the first metallic thin film layer, the solder layer, and the second metallic thin film layer form a structure having a total thickness of (5-25) μm and a periphery of the first metallic thin film layer is recessed from a periphery of the second electrode layer by a predetermined amount.

A semiconductor laser device fabrication method comprising:

• supplying a p-type electrode;
• depositing a first metallic thin film on a side of said p-type electrode, said side facing a substrate;
• thermally processing said first metallic thin film and said p-type electrode at a predetermined temperature for a predetermined time;
• and
• cooling down said first metallic thin film and said p-type electrode, wherein said p-type electrode and said first metallic thin film include Au.

A semiconductor laser module comprising:

• a semiconductor laser element comprising an active layer disposed between first and second electrodes that inject a current into said active layer;
• a first metallic thin film layer provided on a surface of the second electrode;
• a submount having electric insulating and high thermal conductivity properties, said submount having a second metallic thin film layer provided on a surface of the submount;
• and
• a solder layer configured to connect the first metallic thin film layer to the second metallic thin film layer,
• wherein the second electrode, the first metallic thin film layer, the solder layer, and the second metallic thin film layer each comprises Au, and
• wherein the second electrode, the first metallic thin film layer, the solder layer, and the second metallic thin film layer form a structure having a total thickness of 5 to 25 μm;
• a temperature-measuring element which measures a driving temperature of said semiconductor laser element;
• and
• a temperature control element which controls a temperature of said semiconductor laser device in accordance with a temperature output from said temperature-measuring element, wherein
• said submount is connected to an upper part of said temperature control element and the temperature of said semiconductor laser device is controlled through the submount.

A semiconductor laser module comprising:

• a semiconductor laser element comprising an active layer disposed between first and second electrodes that inject a current into an active layer;
• a first metallic thin film layer provided on a surface of the second electrode;
• a submount having electric insulating and high thermal conductivity properties, said submount having a second metallic thin film layer provided on a surface of the submount;
• and
• a solder layer configured to connect the first metallic thin film layer to the second metallic thin film layer,
• wherein a periphery of the first metallic thin film layer is recessed from a periphery of the second electrode layer by a predetermined amount,
• wherein the second electrode, the first metallic thin film layer, the solder layer, and the second metallic thin film layer each comprises Au, and
• wherein the second electrode, the first metallic thin film layer, the solder layer, and the second metallic thin film layer form a structure having a total thickness of 5 to 25 μm;
• a temperature-measuring element which measures a driving temperature of said semiconductor laser element;
• and
• a temperature control element which controls a temperature of said semiconductor laser device in accordance with a temperature output from said temperature-measuring element, wherein
• said submount is connected to an upper part of said temperature control element and the temperature of said semiconductor laser device is controlled through the submount.