Sumitomo Electric Device Innovations, Inc.

Sumitomo Electric Industries, Limited

Toru Ukai

Moriyasu Ichino

Tadashi Sakai

Hiroto Ishibashi

Hidemi Sone

Yuanzhe Li

A method to control an optical transceiver, in particular, to drive an LD installed within the optical transceiver is described. The LD in the bias current thereof is determined by the automatic power control (APC) loop to keep an average of the optical output power. The modulation current is determined by a feedback loop to keep the extinction ratio (ER) in a preset range. The initial condition of the modulation current for the feedback loop is set by T-Im characteristic. The T-Im characteristic is first derived based on data measured in a status of the LD not installed in the transceiver. The T-Im characteristic is revised timely by the modulation current practically obtained for the optical transceiver.

Method to produce optical transceiver

An optical transceiver provides a TOSA, a ROSA, a base member, a circuit board and a shield member. The shield member is formed by cutting and bending a metal sheet without welding or soldering. The shield member includes a center partition and a pair of sides, which forms two spaces each receiving the TOSA or the ROSA. The center partition has a V-shaped cross section which is able to be inserted into a cut of the circuit board so as to shield the ROSA from the TOSA. The shield member provides a frame ground by being in the bottom of the center partition in contact with the base member and also in contact with the cover.

Optical transceiver with a shield member between two OSAS

A method to control an LD (laser diode) is disclosed. The method compares the operating temperature of the LD with a transition temperature. When the former temperature exceeds the latter, the modulation current is set based on the bias current, which is independently determined by the APC loop. On the other hand, the operating temperature is less than the transition temperature; the modulation current is determined by the operating temperature.

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Yokohama, Japan

Toru Ukai