Apparatus and method for setting AC bias point of an optical transmitter module in an optoelectronic transceiver

A method for establishing an AC bias level for a laser diode in an optoelectronic transceiver, comprising:

• coupling an optical output of said transceiver to an optical input of said transceiver;
• setting a DC bias level for said laser diode;
• setting an AC bias level for said laser diode to each of a sequence of AC bias level settings;
• receiving from said transceiver a sequence of optical output power measurements, including an average optical output power measurement corresponding to each of said AC bias level settings in said sequence;
• from said received sequence of power level measurements determining a preferred AC bias level setting;
• and
• establishing said preferred AC bias level setting in said transceiver so as to control said AC bias level of said laser diode;
• determining a break point associated with the sequence;
• and
• selecting an AC bias level corresponding to said determined break point.

A method for setting an AC bias level for a laser diode in an optoelectronic transceiver, comprising:

• coupling an optical output of said transceiver to an optical input of said transceiver;
• setting a DC bias level for said laser diode;
• setting an AC bias level for said laser diode to each of a sequence of AC bias level settings;
• receiving from said transceiver a sequence of optical output power measurements, said sequence of optical output power measurements including an average optical output power measurement corresponding to each of said AC bias level settings in said sequence;
• from said received sequence of optical output power measurements determining a preferred AC bias level setting;
• repeating said receiving and determining at a first plurality of temperatures so as to determine a first plurality of AC bias level settings, each corresponding to a respective temperature in said first plurality of temperatures;
• determining from said first plurality of AC bias level settings, a second plurality of AC bias level settings for a second plurality of temperatures, wherein said second plurality of AC bias level settings are greater in number of than said first plurality of AC bias level settings;
• storing said second plurality of AC bias level settings in said transceiver;
• determining a break point associated with the sequence;
• and
• selecting an AC bias level corresponding to said determined break point.

An apparatus for setting the AC bias level of a laser diode in an optoelectronic transceiver, comprising:

• a test apparatus configured to receive a transceiver to be configured, said transceiver having its optical output coupled to its optical input;
• and
• a control apparatus configured to control the operation of said test apparatus and to set an AC bias level of said transceiver based on measurements received from said transceiver;
• wherein said control apparatus is configured to perform a set operations, including:
• set a AC bias level for said laser diode;
• set an AC bias level for said laser diode to each of a predefined sequence of AC bias level settings;
• receive from said transceiver a sequence of optical output power measurements, said sequence at optical output power measurements including an average optical output power measurement corresponding to each of said AC bias level settings in said predefined sequence;
• from said received sequence of optical output power measurements, determine a preferred AC bias level setting;
• store said preferred AC bias level setting in said transceiver so as to control said AC bias level of said laser diode;
• determine a break point associated with the sequence;
• and
• select an AC bias level corresponding to said determined break point.