Laser initialization in firmware controlled optical transceiver

Claim 2

An optical transceiver module comprising: a laser configured to provide an optical output signal having a power level that is based on a bias current level; and a controller configured to cause the laser to be biased with a bias current having a bias current level, to receive a monitoring signal having a monitoring signal level indicative of the power level, to compare the monitoring signal level to a desired monitoring signal level range substantially centered on a monitoring signal target level, and to adjust the bias current level based on a difference between the monitoring signal level and monitoring signal target level if the monitoring signal level is not within the desired monitoring signal level range.

Claim 3

The optical transceiver of claim 1 further comprising: a sensor configured to provide the monitoring signal.

Claim 4

The optical transceiver of claim 2 further comprising: a transmitter which includes the sensor and the laser.

Claim 5

The optical transceiver module of claim 1 , wherein the laser provides the optical output signal at a power level within a desired power level range when the monitoring signal level is within the monitoring signal level range.

Claim 8

The method of claim 5 further comprising: providing the monitoring signal.

Claim 9

The method of claim 5 further comprising: providing the optical output signal having a power level within a desired power level range when the monitoring signal level is within the desired monitoring signal level range.

Claim 10

The method of claim 5 further comprising: biasing the laser initially with an initial bias current level which is determined at manufacture to cause the laser to provide an optical output signal having a power level resulting in the monitoring signal having a monitoring signal level within the desired monitoring signal level range; and adjusting the initial bias current to reflect a present optical transceiver module temperature prior to biasing the laser with the initial bias current level.

Claim 13

The method of claim 9 further comprising: determining a laser monitor current level with the laser bias current value at the adjusted value; and determining a second difference (Δ 2 ) between the laser monitor current level with the laser bias current value at the adjusted value and the laser monitor current target level.

Claim 14

The method of claim 10 further comprising: setting the laser bias current value to a new adjusted value based on Δ 2 .

Claim 15

The method of claim 9 further comprising: indexing a look-up table with Δ to provide a bias current variable; setting the laser bias current to the adjusted value based on the bias current variable.

Claim 16

The method of claim 12 wherein the bias current variable is an incremental current value, wherein the method comprises: setting the laser bias current to the adjusted value which is substantially equal to the first value plus the incremental current value.

Claim 17

The method of claim 9 further comprising: indexing a look-up table with Δ to provide a bias current variable; and evaluating the bias current variable to determine if the laser bias current is to be adjusted.

Claim 18

The method of claim 9 further comprising: setting the laser bias current initially to a bias current level which is determined at manufacture to result in the laser monitor current level being within the desired laser monitor current level range; and adjusting the initial bias current level to reflect a present optical transceiver module temperature prior to setting the laser bias current to the initial bias current level.

Claim 19

The method of claim 9 further comprising: multiplying a gain by Δ; setting the laser bias current to the adjusted value based on the gain multiplied by Δ.

Claim 20

The method of claim 16 wherein the method comprises: setting the laser bias current to the adjusted value which is substantially equal to the first value minus the gain multiplied by Δ.

Claim 21

The method of claim 9 further comprising: multiplying a gain by Δ; and evaluating the gain multiplied by Δ to determine if the laser bias current is to be adjusted.

Claim 22

The method of claim 9 further comprising: setting the laser bias current to the adjusted value which is less than the first value if the first laser monitor current is greater than the laser target current.

Claim 23

The method of claim 19 comprising: setting the laser bias current to the adjusted value which is substantially equal to the first value minus a constant if the first laser monitor current is greater than the laser target current.

Claim 24

The method of claim 9 further comprising: setting the laser bias current to the adjusted value which is greater than the first value if the first laser monitor current is less than the laser target current.

Claim 25

The method of claim 21 comprising: setting the laser bias current to the adjusted value which is substantially equal to the first value plus a constant if the first laser monitor current is less than the laser target current.

Claim 26

The method of claim 9 further comprising: evaluating Δ to determine if the laser bias current is to be adjusted.

Claim 27

The method of claim 23 further comprising: evaluating the absolute value of Δ to determine if the laser bias current is to be adjusted.

Claim 28

The method of claim 9 further comprising: evaluating a sign of Δ to determine if the laser bias current is to be adjusted with a coarse granularity adjustment or with a fine granularity adjustment.

Claim 29

The method of claim 9 further comprising: setting the laser bias current to the adjusted value with a coarse granularity adjustment.

Claim 30

The method of claim 26 further comprising: determining a second laser monitor current with the laser bias current at the adjusted value; determining a second difference (Δ 2 ) between the second laser monitor current and the laser target current; setting the laser bias current to a new adjusted value with a fine granularity adjustment based on Δ 2 .

Claim 31

The method of claim 26 further comprising: determining a second laser monitor current with the laser bias current at the adjusted value; determining a second difference (Δ 2 ) between the second laser monitor current and the laser target current; and comparing the sign of Δ 2 to the sign of Δ.

Claim 32

The method of claim 28 further comprising: if the sign of Δ 2 is the same as the sign of Δ, setting the laser bias current to a new adjusted value with the coarse granularity adjustment.

Claim 33

The method of claim 28 further comprising: if the sign of Δ 2 is the different than the sign of Δ, setting the laser bias current to a new adjusted value with a fine granularity adjustment.

Claim 34

The method of claim 9 comprising: if the absolute value of Δ is greater than a desired value, setting the laser bias current to the adjusted value.

Claim 35

The method of claim 31 further comprising: setting the laser bias current to the adjusted value which is less than the first value if Δ is greater than zero.

Claim 36

The method of claim 32 comprising: setting the laser bias current to the adjusted value which is substantially equal to the first value minus a constant if Δ is greater than zero.

Claim 37

The method of claim 31 further comprising: setting the laser bias current to the adjusted value which is greater than the first value if Δ is less than zero.

Claim 38

The method of claim 34 comprising: setting the laser bias current to the adjusted value which is substantially equal to the first value plus a constant if Δ is less than zero.

Claim 41

The method of claim 36 further comprising: providing the laser bias current initially at a bias current value which is determined at manufacture to result in the laser monitor current being within the desired range; and adjusting the initially provided bias current value to reflect a present optical transceiver module temperature prior to providing the initially provided bias current value.

Claim 42

An optical transceiver module comprising: a laser configured to provide an optical output signal having a power level that is based on a laser bias current level; means for setting the laser bias current to a bias current level; means for determining a laser monitor current indicative of the power level; means for comparing the laser monitor current to a desired range substantially centered on a laser monitor target current; means for determining a difference between the laser monitor current and laser monitor target current if the laser monitor current is not within the desired range, wherein the laser monitor target current is within the desired range; and means for adjusting the laser bias current level based on the difference.

Claim 43

An optical transceiver module comprising: a laser configured to provide an optical output signal having a power level that is based on a laser bias current level; means for setting the laser bias current to a bias current level; means for determining a laser monitor current indicative of the power level; means for comparing the laser monitor current to a desired range substantially centered on a laser monitor target current; means for determining a difference between the laser monitor current and laser monitor target current if the laser monitor current is not within the desired range, wherein the laser monitor target current is within the desired range; and means for adjusting the laser bias current level based on the difference.

Claim 44

An optical transceiver module comprising: a laser configured to provide an optical output signal having a power level that is based on a laser bias current; means for providing the laser bias current at a bias current value; means for determining a laser monitor current with the laser bias current at the bias current value; means for determining if the laser monitor current with the laser bias current at the bias current value is within a desired range; means for incrementing the bias current value by an amount to provide an incremented bias current value if the laser monitor current is not within the desired range; means for determining a laser monitor current with the laser bias current at the incremented bias current value; and means for adjusting the laser bias current based on the bias current value, the laser monitor current with the laser bias current at the bias current value, the incremented bias current value, and the laser monitor current with the laser bias current at the incremented bias current value.

Claim 45

An optical transceiver module comprising: a laser configured to provide an optical output signal having a power level that is based on a laser bias current; means for providing the laser bias current at a bias current value; means for determining a laser monitor current with the laser bias current at the bias current value; means for determining if the laser monitor current with the laser bias current at the bias current value is within a desired range; means for incrementing the bias current value by an amount to provide an incremented bias current value if the laser monitor current is not within the desired range; means for determining a laser monitor current with the laser bias current at the incremented bias current value; and means for adjusting the laser bias current based on the bias current value, the laser monitor current with the laser bias current at the bias current value, the incremented bias current value, and the laser monitor current with the laser bias current at the incremented bias current value.

Claim 46

The optical transceiver module of claim 1 , wherein the bias current level is adjusted by an amount based on a magnitude of the difference between the monitoring signal level and the monitoring signal target level.

Claim 47

The optical transceiver module of claim 1 , wherein the bias current level is adjusted based on a sign of a difference between the monitoring signal and the monitoring signal target level.

Claim 48

The optical transceiver module of claim 1 , wherein the controller initially biases the laser with a bias current having an initial bias current level which is determined at manufacture to cause the laser to provide an optical output signal having a power level resulting in the monitoring signal having a monitoring signal level within the desired monitoring signal level range.

Claim 49

An optical transceiver module comprising: a laser configured to provide an optical output signal having a power level based on a bias current level; and a controller configured to cause the laser to be biased with a bias current having a first level, to receive a monitoring signal having a first monitoring signal level indicative of the power level corresponding to the first bias current level, to compare the first monitoring signal level to a desired range, to cause the laser to be biased with a second bias current level when the first monitoring signal level is not within the desired range and to receive a second monitoring signal level indicative of the power level corresponding to the second bias current level, and to cause the laser to be biased with an adjusted bias current level based on the first and second bias current levels and the corresponding first and second monitoring signal levels.

Claim 50

An optical transceiver module comprising: a laser configured to provide an optical output signal having a power level based on a bias current level; and a controller configured to cause the laser to be biased with a bias current having a first level, to receive a monitoring signal having a first monitoring signal level indicative of the power level corresponding to the first bias current level, to compare the first monitoring signal level to a desired range, to cause the laser to be biased with a second bias current level when the first monitoring signal level is not within the desired range and to receive a second monitoring signal level indicative of the power level corresponding to the second bias current level, and to cause the laser to be biased with an adjusted bias current level based on the first and second bias current levels and the corresponding first and second monitoring signal levels.

Claim 51

The optical transceiver module of claim 43 , wherein the second bias current level is an incremental amount greater than the first bias current level.

Claim 52

The optical transceiver module of claim 43 , wherein the first bias current level comprises a level determined at manufacture to cause the laser to provide an optic output signal having a power level resulting in the monitoring signal having a monitoring signal level within the desired range.

Claim 53

The optical transceiver module of claim 45 , wherein the first bias current level is stored in a memory internal to the controller.

Claim 54

The optical transceiver module of claim 43 , wherein the adjusted bias level is based on an extrapolation from the first and second bias current levels and the corresponding first and second monitoring signal levels.

Claim 55

The method of claim 36 , further comprising: adjusting the laser bias current by extrapolating from the bias current value, the laser monitor current with the laser bias current at the bias current value, the incremented bias current value, and the laser monitor current with the laser bias current at the incremented bias current value.