Oracle International Corporation

Oracle America, Inc.

Dinesh D Patil

Frankie Liu

Ronald Ho

Ashok V Krishnamoorthy

Elad Alon

Philip Amberg

An optical device that includes a wavelength-sensitive optical component, which has an associated thermal time constant, is described. Note that an operating wavelength of the wavelength-sensitive optical component is a function of several physical parameters including temperature. Moreover, the optical device includes a heating mechanism that provides heat to the wavelength-sensitive optical component. Furthermore, the optical device includes a driver circuit that provides a pulse-width modulated signal to the heating mechanism. Note that an average pulse-width modulated heat provided by the heating mechanism, and which corresponds to the pulse-width modulated signal, thermally tunes the wavelength-sensitive optical component to a target operating wavelength. Additionally, note that the target operating wavelength corresponds to a target operating temperature of the wavelength-sensitive optical component.

Pulse-width-modulated thermal tuning of optical devices

An optical receiver is described. This optical receiver has two operating modes: a calibration mode and a normal mode. During the normal mode, switches are used to electrically couple an input of a transimpedance amplifier (TIA) to an optical-to-electrical (OE) converter that receives an optical signal and provides a corresponding analog electrical signal. Moreover, during the calibration mode, the switches are used to electrically isolate the input of the TIA from the OE converter while maintaining a feedback path from an output of the TIA to the input of the TIA, thereby ensuring proper bias of the TIA during calibration. Furthermore, a frequency response of the TIA during the normal mode is substantially unchanged over an operating bandwidth of the TIA by the capability to electrically isolate the input of the TIA from the OE converter during the calibration mode.

Input isolation of a transimpedance amplifier in optical receivers

An optical receiver is described. This optical receiver includes a digital feedback circuit that biases a front-end circuit, which receives an optical signal, so that an analog electrical signal output by the front-end circuit is calibrated relative to a reference voltage corresponding to a decision threshold of a digital slicer in the optical receiver. In particular, during a calibration mode the feedback circuit may determine and store a calibration value that calibrates the analog electrical signal relative to the reference voltage. Then, during a normal operating mode, the feedback circuit may output a current corresponding to the stored calibration value that specifies a bias point of the front-end circuit.

Optical receiver with a calibration mode

A technique for calibrating an optical receiver is described. During this technique, a front-end circuit in the optical receiver receives an optical signal that corresponds to a sequence with alternating groups of symbol types that correspond to binary values, where durations of the groups of a given symbol type, which can correspond to a first binary value or a second binary value, progressively decrease during the sequence. Then, the output of the feedback circuit is adjusted based at least on the sequence. When the durations of groups corresponding to the first binary value and the second binary value reach their minimum values in the sequence, a calibration value corresponding to the output of the feedback circuit is stored for use during a normal operating mode of the optical receiver.

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Fremont, CA, United States of America

Dinesh D Patil