Semiconductor laser driving apparatus, electronic equipment, and manufacturing method of semiconductor laser driving apparatus
To reduce the wiring inductance between a semiconductor laser and a laser driver in a semiconductor laser driving apparatus. A substrate incorporates a laser driver. A semiconductor laser is mounted on one surface of the substrate of a semiconductor laser driving apparatus to emit irradiation light from an irradiation surface. Connection wiring electrically connects the laser driver and the semiconductor laser to each other with a wiring inductance of 0.5 nanohenries or less. A first optical element is provided on the irradiation surface side of the semiconductor laser. A second optical element is provided outside the first optical element on the irradiation surface side of the semiconductor laser.
1 . A semiconductor laser driving apparatus, comprising:
a substrate incorporating a laser driver;
a first semiconductor laser mounted on one surface of the substrate to emit irradiation light from an irradiation surface;
a second semiconductor laser mounted on the one surface of the substrate to emit irradiation light from an irradiation surface;
connection wiring that electrically connects the laser driver and the first semiconductor laser to each other with a wiring inductance of 0.5 nanohenries or less and that electrically connects the laser driver and the second semiconductor laser to each other with a wiring inductance of 0.5 nanohenries or less;
a first optical element provided on an irradiation surface side of the first and second semiconductor lasers, wherein the first optical element includes a first region and a second region, wherein the first region of the first optical element is a transmission portion that allows irradiation light from the first semiconductor laser to pass therethrough, wherein the first region of the first optical element does not include a collimator lens, and wherein the second region of the first optical element includes a collimator lens that makes irradiation light from the second semiconductor laser into parallel light; and
a second optical element provided outside the first optical element on the irradiation surface side of the first and second semiconductor lasers.
2 . The semiconductor laser driving apparatus according to claim 1 ,
wherein
the second optical element is a diffractive optical element that diffracts the parallel light.
3 . The semiconductor laser driving apparatus according to claim 2 ,
wherein the first optical element includes a microlens array.
4 . The semiconductor laser driving apparatus according to claim 1 ,
wherein the second optical element includes a diffusion element that refracts light having passed through the first region of the first optical element and a diffractive optical element that diffracts the parallel light from the second region of the first optical element, wherein the second optical element includes a diffusion element that refracts light output by the first semiconductor laser and that is received as spreading light from the first region of the first optical element, and wherein the second optical element includes a diffractive optical element that diffracts light output by the second semiconductor laser and that is received as parallel light from the second region of the first optical element.
5 . The semiconductor laser driving apparatus according to claim 1 ,
wherein the connection wiring connecting the laser driver and the first semiconductor laser has a length of 0.5 millimeters or less.
6 . The semiconductor laser driving apparatus according to claim 1 ,
wherein the connection wiring connecting the laser driver and the first semiconductor laser is provided via a connection via provided in the substrate.
7 . The semiconductor laser driving apparatus according to claim 1 ,
wherein the first semiconductor laser is arranged in such a manner that a part thereof overlaps an upper part of the laser driver.
8 . The semiconductor laser driving apparatus according to claim 7 ,
wherein the first semiconductor laser is arranged in such a manner that a part corresponding to 50% or less of an area thereof overlaps the upper part of the laser driver.
9 . The semiconductor laser driving apparatus according to claim 1 , wherein the second optical element includes a diffusion element that refracts light output by the first semiconductor laser that is received at the diffusion element as spreading light from the first region of the first optical element, and wherein the second optical element includes a diffraction element that diffracts light output by the second semiconductor laser that is received at the diffraction element as parallel light from the second region of the first optical element.
10 . Electronic equipment, comprising:
a substrate incorporating a laser driver;
a first semiconductor laser mounted on one surface of the substrate to emit irradiation light from an irradiation surface;
a second semiconductor laser mounted on the one surface of the substrate to emit irradiation light from an irradiation surface;
connection wiring that electrically connects the laser driver and the first semiconductor laser to each other with a wiring inductance of 0.5 nanohenries or less and that electrically connects the laser driver and the second semiconductor laser to each other with a wiring inductance of 0.5 nanohenries or less;
a first optical element provided on an irradiation surface side of the first and second semiconductor lasers, wherein the first optical element includes a first region and a second region, wherein the first region of the first optical element is transmission portion that allows irradiation light from the first semiconductor laser to pass therethrough, wherein the first region of the first optical element does not include a collimator lens, and wherein the second region of the first optical element includes a collimator lens that makes irradiation light from the second semiconductor laser into parallel light; and
a second optical element provided outside the first optical element on the irradiation surface side of the first and second semiconductor lasers.
11 . A manufacturing method of a semiconductor laser driving apparatus, comprising:
a step of forming a laser driver on an upper surface of a support plate;
a step of forming a substrate incorporating the laser driver, by forming connection wiring of the laser driver;
a step of mounting a first semiconductor laser on one surface of the substrate and forming connection wiring that electrically connects the first laser driver and the semiconductor laser to each other via the connection wiring with a wiring inductance of 0.5 nanohenries or less;
a step of mounting a second semiconductor laser on one surface of the substrate and forming connection wiring that electrically connects the laser driver and the semiconductor laser to each other via the connection wiring with a wiring inductance of 0.5 nanohenries or less;
a step of forming a first optical element on an irradiation surface side of the first and second semiconductor lasers, wherein the first optical element includes a first region and a second region, wherein the first region of the first optical element is a transmission portion that allows irradiation light from the first semiconductor laser to pass therethrough, wherein the first region of the first optical element does not include a collimator lens, and wherein the second region of the first optical element includes a collimator lens that makes irradiation light from the second semiconductor laser into parallel light;
and a step of forming a second optical element outside the first optical element on the irradiation surface side of the first and second semiconductor lasers.