Fujitsu Corporation

Gan Oda

Akira Okamoto

Hiroyuki Furukawa

Tetsuo Watanabe

Tatsuro Kunikane

Kaoru Moriya

Kenji Tagawa

Yoshimitsu Sakai

Sadayuki Miyata

Makoto Fujihara

Nobuyoshi Horigome

A compact, low-cost combined transmitting/receiving optical communications module, which is suitable for use in a TCM system and which is capable of normal operation over a particularly wide temperature range in optical communications equipment, is provided. The optical transmitting/receiving section for this purpose has a laser diode which outputs a transmitted optical signal, a combined monitor/receiving photodiode which not only monitors the optical output signal from the laser diode during a transmitting period, but also receives the input optical signal from the transmission path during the receiving period, and an optical mixer/divider which performs transmitting/receiving mixing and dividing between the transmission path, the laser diode, and the photodiode. A drive section has a transmitting/receiving switching circuit which performs time-division transmitting/receiving switching and a threshold control circuit which performs successive control of the bias current of the laser diode so that the optical noise output monitored by the photodiode is maximized.

Optical communications module

An optical connector which can prevent that light reflected on an end surface of a ferrule built in the optical connector may be returned to a transmitting side in the open condition of the connector. The optical connector includes a first ferrule and a second ferrule both slidably stored in a housing. The first ferrule has one end spherically polished and another end obliquely polished. The second ferrule has one end obliquely polished. The optical connector further includes a sleeve for coaxially holding the first ferrule and the second ferrule, a first spring for biasing the first and second ferrules away from each other, and a second spring for biasing the second ferrule toward the first ferrule. The first spring has a spring constant greater than that of the second spring.

Optical connector optical adapter and light emitting module

A photodetector module comprising an optical fiber and a photodetector which are coupled by direct optical coupling is disclosed. A photodetector chip is fixedly attached to the circular top surface, having the shape of a circle circumscribed around the photodetector chip, of a carrier having the shape of a frustum of a circular cone, or the photodetector chip is fixedly attached to the circular bottom surface, having the shape of a circle circumscribed around the photodetector chip, of a circular recess formed in the bottom of a taper recess formed in the carrier and having the shape of a frustum of a circular cone. Such a combination of the photodetector chip and the carrier enables the omission of the positional adjustments of the photodetector chip on the carrier with respect to the X-axis and the Y-axis. A ferrule having a flange and a ferrule support member having a taper surface fitting the taper surface of the carrier are employed to omit the positional adjustment of the photodetector chip with respect to the Z-axis. Thus, the photodetector module can be assembled without requiring the positional adjustments of the photodetector chip relative to the optical fiber.

Photodetector module for coupling with optical fiber

Growing community of inventors

Kawasaki, Japan

Gan Oda