Abstract: In one embodiment, a silicon photonic integrated circuit (PIC) includes a pair of Mach-Zehnder Interferometers (MZI) with a phase shifter to function as a 1x2 optical switches. On one path between the MZIs is a wavelength interleaver. The MZI switch can be controlled to either an all-pass mode or a by-pass mode, therefore setting configurable optical demultiplexing bandwidths to support dual 1.6 T FR8/800G FR4 network backward compatibility. The configurable multiplexer operates at set-and-forget mode for the entire operating temperature and the product’s lifetime.

Abstract: Techniques for termination for microring modulators are disclosed. In the illustrative embodiment, a microring modulator on a photonic integrated circuit (PIC) die is modulated by radiofrequency (RF) signals connected to electrodes across the microring modulator. A resistor is connected to each of the electrodes. The resistors both provide termination for the RF signals, preventing or reducing reflections, as well as forming part of a bias tee, allowing for a DC bias voltage to be applied across the electrodes.

Abstract: An amplitude encoded transmission system and method are disclosed that achieve an improved bit-error rate for systems with a non-linear input/output relationship in the presence of noise. A set of measures are determined for adjacent signal levels. The set of measures are compared to each other. When at least one of the set of respective measures does not approximate the remaining measures in the set of measures, one or more signal levels are adjusted until the set of respective measures of the transmitter approximate each other. The method can be applied during a select manufacturing stage of the transmitter. An integrated system includes an optical emitter, modulator, photosensitive diode and signal-level adjuster. The modulator receives a set of control signals to operate the emitter at a desired output level. The photosensitive diode generates a feedback signal that is used by the signal-level adjuster to generate a bias signal.

Abstract: An optical transceiver module includes N light sources, N light detectors, a bidirectional fiber port, and an optical network having 2N?1 wavelength-selective elements. The number 2N represents the total number of transmit and receive channels in a bidirectional system in which transmit and receive signals corresponding to the transmit and receive channels. Each light source corresponds to one transmit channel and emits an optical transmit signal having a unique transmit wavelength. Each light detector corresponds to one receive channel and detects an optical receive signal having a unique receive wavelength. The optical network couples each light source to the bidirectional fiber port via a corresponding transmit path through the optical network. The optical network further couples each light detector to the bidirectional fiber port via a corresponding receive path through the optical network. Each transmit and receive path includes some of the wavelength-selective elements.

Abstract: An optical communication system includes a transceiver with a light source, a transition lens and an optical medium. Each of the light source, the transition lens and the optical medium define a corresponding axis. The light source defines a normal launch axis. The transition lens defines an optical axis. The optical medium defines a longitudinal axis. A relative misalignment from a coaxial alignment of the corresponding axes of at least one the light source, the transition lens and the optical medium is used to reduce a back reflection incident at the light source. Such misalignments can be achieved by one or both of angular adjustments and offsets of the axes.

Abstract: A bidirectional optical communication system includes first and second transceivers arranged at opposed ends of an optical medium. Opto-electronic devices within the transceivers are arranged on respective mounting surfaces of planar substrates. First and second optical assemblies couple the respective transceivers to the optical medium. The optical assemblies include first and second optical elements arranged along an axis normal to the substrates. The first optical element is transparent to the optical signal transmitted from the respective transceiver and redirects the received optical signal from the other transceiver. The optical assemblies enable a single alignment of the opto-electronic devices and the optical medium.

Abstract: An adapter includes a housing with opposed openings for receiving a first connector that is mechanically and optically mateable with a second connector to form one or more optical signal communication links. The housing is arranged with a slot for receiving a flexible material having an index of refraction that approximates the index of refraction of aligned pairs of optical fibers. The flexible material is appropriately sized to cover the fibers from each of the connectors. The optical fiber ends of a respective connector can be cleaned by inserting the connector in the adapter and advancing the flexible material. Once the optical fiber ends of both connectors have been cleaned and the flexible material further advanced, the connectors can be reinserted in the adapter to establish an optical signal link between the optical fibers.

Abstract: A communication device utilizing an interrupting alignment pattern is disclosed. The communication device may comprise a plurality of inputs, a pattern generator, a multiplexer, a control circuit, an interrupt circuit, and an output. The pattern generator may be configured to generate an alignment pattern. The control circuit may be configured to control the multiplexer to multiplex a plurality of incoming data streams into a serialized output data stream. The interrupt circuit may be configured to interrupt the serialized output data stream with the alignment pattern. The output may be configured to output the alignment pattern in place of the serialized output data stream, when the serialized output data stream is interrupted by the alignment pattern.

Abstract: In an optical data communication system transmitter, in which a laser is driven with a laser modulation signal in response to a serial data stream, the laser driver adds peaking to a bit other than the first bit following a bit transition.

Abstract: A controller and methods for adaptively adjusting a dispersion compensation circuit in a receiver of a communication link are disclosed. The controller receives a signal from an error detector coupled to the receiver. The controller includes a logic engine that provides configuration information to the dispersion compensation circuit. The configuration information defines a digital filter in response to at least one tap constraint and at least one coefficient constraint. In an example embodiment, the logic engine generates a measure of residual inter-symbol interference and a measure of a noise enhancement penalty and iteratively provides a set of adjusted coefficient values that when applied in the digital filter will result in an equalized receiver output signal that minimizes a mathematical combination of the measure of the residual inter-symbol interference and the measure of the noise enhancement penalty.

Abstract: An optical transceiver module includes N light sources, N light detectors, a bidirectional fiber port, and an optical network having 2N?1 wavelength-selective elements. The number 2N represents the total number of transmit and receive channels in a bidirectional system in which transmit and receive signals corresponding to the transmit and receive channels. Each light source corresponds to one transmit channel and emits an optical transmit signal having a unique transmit wavelength. Each light detector corresponds to one receive channel and detects an optical receive signal having a unique receive wavelength. The optical network couples each light source to the bidirectional fiber port via a corresponding transmit path through the optical network. The optical network further couples each light detector to the bidirectional fiber port via a corresponding receive path through the optical network. Each transmit and receive path includes some of the wavelength-selective elements.

Abstract: An optical communication system includes a transceiver with a light source, a transition lens and an optical medium. Each of the light source, the transition lens and the optical medium define a corresponding axis. The light source defines a normal launch axis. The transition lens defines an optical axis. The optical medium defines a longitudinal axis. A relative misalignment from a coaxial alignment of the corresponding axes of at least one the light source, the transition lens and the optical medium is used to reduce a back reflection incident at the light source. Such misalignments can be achieved by one or both of angular adjustments and offsets of the axes.

Abstract: An adapter includes a housing with opposed openings for receiving a first connector that is mechanically and optically mateable with a second connector to form one or more optical signal communication links. The housing is arranged with a slot for receiving a flexible material having an index of refraction that approximates the index of refraction of aligned pairs of optical fibers. The flexible material is appropriately sized to cover the fibers from each of the connectors. The optical fiber ends of a respective connector can be cleaned by inserting the connector in the adapter and advancing the flexible material. Once the optical fiber ends of both connectors have been cleaned and the flexible material further advanced, the connectors can be reinserted in the adapter to establish an optical signal link between the optical fibers.

Abstract: In an optical data communication system transmitter, in which a laser is driven with a laser modulation signal in response to a serial data stream, the laser driver adds peaking to a bit other than the first bit following a bit transition.