Ntt Corporation

Shigeru Kanazawa

Takahiko Shindo

Yasuhiko Nakanishi

Shoko Tatsumi

Masahiro Nada

Naoki Fujiwara

Meishin Chin

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

An optical transmitter capable of significantly suppressing a fluctuation in frequency response characteristics due to a fabrication error in internal wire length while reducing a subcarrier size of a module of the optical transmitter is provided. The optical transmitter includes a subcarrier on which an RF wiring board, a modulated laser chip, and a terminating resistor are mounted. A ground pad is on an upper surface of the subcarrier. A wire electrically connects at least the RF wiring board and the modulated laser chip to each other. The RF wiring board and the modulated laser chip are arranged in a width direction of the subcarrier. A length of the wire in an electric path which starts at the RF wiring board, passes through the terminating resistor, and reaches the ground pad is 0.5 to 1.5 mm or has an inductance of 0.4 to 1.2 nH.

Growing community of inventors

Musashino, Japan

Shigeru Kanazawa