Abstract: A plurality of lead pins (2a-d) penetrates through a stem (1) having a circular shape and includes a signal lead pin (2a,2b). A block (4) is provided on an upper surface of the stem. A waveguide light receiving device (9) is provided on a side surface of the block. An amplifier (6) is provided on the side surface of the block and amplifies an electric signal output from the waveguide light receiving device. A first relay substrate is provided on the upper surface of the stem and arranged between the block and the signal lead pin. A first transmission line (12a,12b) is provided on the first relay substrate. A first wire (10f,10g) connects one end of the first transmission line and an output terminal of the amplifier. A second wire (10h,10i) connects the other end of the first transmission line (12a,12b) and the signal lead pin.

Abstract: A plurality of lead pins (2a-d) penetrates through a stem (1) having a circular shape and includes a signal lead pin (2a,2b). A block (4) is provided on an upper surface of the stem. A waveguide light receiving device (9) is provided on a side surface of the block. An amplifier (6) is provided on the side surface of the block and amplifies an electric signal output from the waveguide light receiving device. A first relay substrate is provided on the upper surface of the stem and arranged between the block and the signal lead pin. A first transmission line (12a,12b) is provided on the first relay substrate. A first wire (10f,10g) connects one end of the first transmission line and an output terminal of the amplifier. A second wire (10h,10i) connects the other end of the first transmission line (12a,12b) and the signal lead pin.

Abstract: This optical transmission module includes: a plurality of semiconductor lasers provided on a sub-mount fixed to a side surface of a block fixed on a plate-shaped stem made of metal; and a cap with a lens fixed thereto, the cap covering all members placed above the stem. The same number of lead pins as the semiconductor lasers are provided so as to respectively penetrate through a plurality of holes formed in the stem. The lead pins and the semiconductor lasers are electrically connected to each other, respectively. Single-phase electrical signals with the stem as a ground potential are respectively applied to the semiconductor lasers from an external power supply, through the lead pins, respectively, so as to cause modulation and oscillation of the semiconductor lasers.

Abstract: Output terminals of a TIA and front electrodes of dielectric substrates are electrically connected by wires, output lead pins and the front electrodes are electrically connected by wires, and output signals of the TIA are outputted, via the dielectric substrates, to the output lead pins.

Abstract: A substrate has a front surface and a back surface opposite from the front surface. An n-type layer, a multiplication layer, a p-type electric field control layer, a light absorption layer, and a window layer are layered in order on the front surface. A p-type region is provided in part of the window layer. An anode electrode is provided on the p-type region and connected to the p-type region. An anode pad and a cathode pad are provided on the back surface. First and second connecting holes penetrates the substrate. A third connecting hole penetrates from the window layer to the n-type layer. The cathode pad is electrically connected to the n-type layer via the first connecting hole. The anode pad is electrically connected to the anode electrode via the second and third connecting holes. A light-receiving region is provided on the back surface.

Abstract: A substrate has a front surface and a back surface opposite from the front surface. An n-type layer, a multiplication layer, a p-type electric field control layer, a light absorption layer, and a window layer are layered in order on the front surface. A p-type region is provided in part of the window layer. An anode electrode is provided on the p-type region and connected to the p-type region. An anode pad and a cathode pad are provided on the back surface. First and second connecting holes penetrates the substrate. A third connecting hole penetrates from the window layer to the n-type layer. The cathode pad is electrically connected to the n-type layer via the first connecting hole. The anode pad is electrically connected to the anode electrode via the second and third connecting holes. A light-receiving region is provided on the back surface.

Abstract: A semiconductor light-receiving device includes: a substrate; a p-type conductive layer, a light absorption layer having a smaller bandgap than that of incident light, a multiplication layer producing avalanche multiplication, and an n-type window layer laminated in that order on the substrate; an n-type conductive layer in a region of part of the n-type window layer; and a first p-type conductive region in a region of the n-type window layer that is not in contact with the n-type conductive layer, wherein the first p-type conductive region does not reach the multiplication layer and is not in contact with any electrode to which power is supplied from outside.

Abstract: A light receiving element includes a substrate of a first conduction type, a light absorbing layer of the first conduction type formed on the substrate, a diffusion layer of a second conduction type formed on a portion of the light absorbing layer, a window layer of the first conduction type formed on the light absorbing layer so as to surround the diffusion layer and having a bandgap larger than that of the light absorbing layer, an anode electrode formed on the diffusion layer, and a cathode electrode provided on the substrate so as to contact the substrate without contacting each of the window layer and the light absorbing layer, wherein a groove is formed which surrounds a boundary between the diffusion layer and the window layer as viewed in plan and extends through the window layer and the light absorbing layer as viewed in section.

Abstract: A light receiving element includes a substrate of a first conduction type, a light absorbing layer of the first conduction type formed on the substrate, a diffusion layer of a second conduction type formed on a portion of the light absorbing layer, a window layer of the first conduction type formed on the light absorbing layer so as to surround the diffusion layer and having a bandgap larger than that of the light absorbing layer, an anode electrode formed on the diffusion layer, and a cathode electrode provided on the substrate so as to contact the substrate without contacting each of the window layer and the light absorbing layer, wherein a groove is formed which surrounds a boundary between the diffusion layer and the window layer as viewed in plan and extends through the window layer and the light absorbing layer as viewed in section.

Abstract: A photo diode array includes: a substrate having a major face and a back face; photo diodes separated from each other and arrayed in parallel on the major face of the substrate and being linear in a plan view facing the major face of the substrate; a buried layer between the photo diodes and including a separating channel having a V-shape cross section; and a first metal mirror on an inclined face of the separating channel, reflecting incident light entering from the back face of the substrate, and leading the incident light to light-absorbing layers of the photo diodes. Band gap energy of the buried layer is wider than band gap energies of the light-absorbing layers.