Agilent Technologies, Inc.

Avago Technologies Fiber IP (singapore) Pte. Ltd

Other

Avago Technologies Fiber IP Pte Ltd.

Gideon Z Romm

Michael Allen Robinson

Randall P Clark

Frederick W Miller

A method for a laser system to compensate a variability of a signal converter in the laser system includes generating a temperature signal corresponding to a temperature of a laser and adjusting a signal of the signal converter based on at least the temperature signal. A laser transceiver includes a memory, a controller, a bandwidth circuit, and a modulation driver. The controller generates at least one control signal set by a host in the memory. The bandwidth circuit is a programmable low-pass filter (LPF) receiving the control signal and at least one input terminal receiving at least one data signal. The programmable LPF filters the data signal based on the control signal. The modulation driver has at least one input terminal receiving the filtered data signal. The modulation driver provides a modulation current to a laser in response to the filtered data signal.

Calibration of laser systems

A method for a fiber optic device to conserve power includes turning off components in the fiber optic device and turning them back on when a detection signal is at a specified level. A method for a laser system to adjust a threshold level for signal detection includes generating a digital gain signal, amplifying at least one data signal with a gain based on the gain signal, comparing the at least one amplified data signal with a reference signal, and generating a signal based on the comparison. A method for a laser system to set error warnings includes receiving control bits that indicate if a host desires to be notified of certain error conditions and generating at least one signal based on the control bits to indicate at least one error condition.

Loss of signal detection and programmable behavior after error detection

A method for determining a condition of the laser system includes determining a change in a laser current from an initial value. A method for measuring a laser current includes determining a difference between the values of a power supply current, which is the value of the laser current. A method for measuring a transmitted power includes generating a first control signal that sets a magnitude of a bias current supplied to a laser, generating a second control signal that sets a of a modulation current supplied to the laser, and determining a difference between values of a high and a low transmitted powers. A method for measuring a received optical power includes determining a received OMA corresponding to the power signal, which is the transmitted OMA minus a known loss through a calibration fiber that couples the laser transmitter to the laser receiver.

A method for determining a condition of the laser system includes determining a change in a laser current from a preset value. The method includes determining the preset value based on a temperature signal and a supply voltage signal for the laser. The preset value can be determined from a table or from a function.

A method for controlling a laser includes determining an average component of a laser drive current and adjusting a modulation component of the drive current based on the average component and a threshold current signal at the present temperature. Determining the average component includes adjusting the drive current until an output power of the laser is approximately equal to a reference signal that varies according to temperature. The method further includes calibrating the threshold current signal, which includes adjusting the drive current until the laser output power is approximately equal to a second reference signal, and storing the drive current signal as the threshold current signal at the present temperature. The method further includes recalibrating the threshold current signal, which includes storing a difference between a new value and a stored value of the threshold current signal as an offset for other stored values of the threshold current signal.

Control and calibration of laser systems

A driver circuit for an opto-electrical transmitter includes a digital feedback loop. A counter in the feedback loop maintains a count that controls a bias current output to the opto-electrical transmitter. A first fault activation circuit in the driver activates a fault signal that disables the driver when the count causes an overflow or underflow. The overflow/underflow can correspond to the input range of an ADC that converts the count into an analog signal to an output amplifier or to the range of the counter. A second fault activation signal times the duration of any periods during which a digital parameter of the driver is outside a target range. The digital parameter can be e a measured monitor current or the count that controls the output amplifier.

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Bronx, NY, United States of America

Gideon Z Romm