Method to produce optical transceiver
AssigneeSumitomo Electric Device Innovations, Inc.
InventorsToru Ukai, Moriyasu Ichino, Tadashi Sakai
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Abstract
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.
Claims6
A method to form an optical transceiver that installs a semiconductor laser diode (LD), comprising steps of:
- before the LD is installed in the optical transceiver, measuring an I-L characteristic of the LD, the I-L characteristic relating a current supplied to the LD with optical power output from the LD;
- installing the LD within the optical transceiver;
- and
- determining a modulation current as varying a temperature of the optical transceiver by a feedback loop with an initial condition by referring to a look-up-table (LUT) relating the modulation current (Im) with temperatures (T), the modulation current being supplied to the LD to keep an extinction ratio of light output from the optical transceiver in a preset range as a bias current (Ib) supplied to the LD is automatically determined by an automatic power control (APC) circuit to keep an average of the optical power output from the LD in a preset level,
- wherein the LUT is revised by replacing data based on the I-L characteristic of the LD with the modulation current practically determined for the light output from the optical transceiver.
Dependencies are inferred from the claim text.