Nippon Telegraph and Telephone Corporation

Ntt Corporation

Yasuhiko Nakanishi

Atsushi Kanda

Toshihide Yoshimatsu

Shigeru Kanazawa

Masahiro Nada

Takahiko Shindo

Meishin Chin

Shoko Tatsumi

An optical transmitter that multiplexes wavelength channels includes: a first light source; one or more second light source each having a different wavelength; collimator lenses coupled to respective outputs of the first and second light sources; an optical multiplexer that causes an output light beam from the first light source to be transmitted from a first end surface to a second end surface, causes the output light beam from the first light source to be reflected by a reflecting mirror, causes an output light beam from the second light source to pass through a wavelength filter, causes the output light beam from the second light source to be reflected by the reflecting mirror, and causes output light beams of the respective wavelength channels, to sequentially multiplex the output light beams of the respective wavelength channels; and beam splitters respectively inserted between the collimator lenses and the first end surface.

Optical transmitter

This semiconductor wafer has formed therein a plurality of chips, each of which has incorporated therein a semiconductor element to be tested. The semiconductor wafer is characterized by comprising: first pads which are formed on the chips, and to which a plurality of probe needles are connected, the probe needles being connected to the semiconductor elements and used for testing the semiconductor elements; and a second pad that is used for performing a contact check on the probe needles, the second pad having a conductive section greater in length than the distance between the centers of the first pads.

Semiconductor wafer

A highly efficient optical burst transmitter is provided. An embodiment is an optical burst transmitter including a control circuit configured to output a data signal and a burst control signal and a semiconductor optical amplifier configured to output an optical data signal modulated using the data signal as an optical burst data signal controlled using the burst control signal, the optical burst transmitter including: an electric line configured to connect the control circuit and the semiconductor optical amplifier and transmit the burst control signal; and an impedance matching circuit configured to impedance-match a characteristic impedance of the electric line and the semiconductor optical amplifier with each other.

Optical burst transmitter

In an optical receiver circuit which suppresses an unnecessary increase in impedance and occurrences of resonance and radiation noise and which produces preferable high-frequency transmission characteristics, a PD submount mounted with a PD chip and a chip capacitor and a TIA carrier mounted with a TIA chip are electrically connected to each other by a bonding wire. The chip includes an anode electrode pad and a cathode electrode pad, anode electrode-side ground pads are formed at positions that sandwich the pad, and cathode electrode-side ground pads are formed at positions that sandwich the pad. A wire electrically connects the pad and a signal pad for input of the chip to each other, a wire electrically connects the pad and the capacitor to each other, and a wire electrically connects the pads and the pads to each other.

Growing community of inventors

Musashino, Japan

Yasuhiko Nakanishi