Abstract: A method and system for performing OTDM. Laser wavelength tuning is used to create appropriate time differentials between bits in a combined optical output data stream.

Abstract: An optical multiplexer is provided that includes a reconfigurable switching fabric with a number of inputs and outputs. In addition, the reconfigurable switching fabric employs VLSOAs that facilitate at least partial reconfiguration of the switching fabric by serving as switches to add, drop or pass-through one or more optical signals received at the inputs of the reconfigurable switching fabric. In some cases, one or more of the VLSOAs also serve to amplify one or more optical signals so as to compensate for losses that may be experienced by the signal in transit through the switching fabric, or elsewhere. Finally, this example of the optical multiplexer includes a wavelength division multiplexer coupled to the reconfigurable switching fabric and configured to multiplex at least some of the optical signals received from outputs of the reconfigurable switching fabric.

Abstract: An optical latch based on a lasing semiconductor optical amplifier is disclosed. The optical latch is configured to achieve one or more stable states in response to the input of predetermined signals at a “SET” input and a “RESET” input of the optical latch. The optical latch includes first and second LSOAs, each of which is configured to receive a pump input and generate an amplifier output. Each LSOA is also associated with a respective combiner and splitter. The combiner associated with each LSOA combines an input signal from the “SET” or “RESET” input, as applicable, with a signal received from the splitter of the other LSOA and the resulting combined signal is then input to the LSOA. Each splitter receives a ballast laser output from the associated LSOA, which is then split into two signals, namely, an input to the combiner of the other LSOA and an output signal.

Abstract: This disclosure is concerned with digital optical circuits, including an optical astable multivibrator. In one example, an optical astable multivibrator is provided that includes a lasing semiconductor optical amplifier (LSOA), such as a VLSOA for example. The LSOA is optically coupled to a time delay component and includes a pump input, amplifier input, amplifier output, and a ballast laser output. The time delay component includes an input that is optically coupled with the ballast laser output of the LSOA. The time delay component further includes an output that is optically coupled with the amplifier input of the LSOA. The output of the LSOA is a clock signal having a periodic square waveform whose frequency is determined by the time delay component.

Abstract: Optical regenerators are disclosed, one of which includes a splitter having an input signal input, and first and second outputs, where the first output is connected to a first input of an optical flip-flop that also includes an output. A first OAND gate includes a first input connected to the output of the optical flip-flop, and also includes a second input and an output. A second OAND gate has a first input connected to the second output of the splitter, and includes a second input and an output. A variable oscillator having an input and an output is arranged so that the output is connected to the second input of the second OAND gate and to the second input of the first OAND gate. Finally, a feedback controller has an input connected to the second OAND gate output, and an output connected to the variable oscillator input.

Abstract: A VLSOA is used as a wavelength converter. The signal is input to the VLSOA, and the laser output carries the signal on a second wavelength.

Abstract: An improved optical receiver comprises a vertically lasing semiconductor optical amplifier (VLSOA) coupled to a photodetector. The VLSOA and photodetector are discrete devices or alternatively integrated onto a common substrate. The integrated optical receiver may be fabricated using a number of different methods, including based on selective area epitaxy, impurity induced disordering, etch and fill and silicon optical bench.

Abstract: A multi-stage tunable gain optical amplifier device amplifies an optical signal by a gain amount which can be adjusted in one of the stages of the amplifier. The multi-stage amplifier includes at least two optical amplifier stages coupled in series, one of which is a tunable gain amplifier stage. The optical amplifier stages are characterized by a design parameter which varies from stage to stage. In a preferred embodiment, the design parameter includes a noise figure and a saturable power, with both parameters increasing as the optical signal propagates from stage to stage. As a result, the multi-stage tunable gain optical amplifier can achieve better noise performance and higher output power than a single stage optical amplifier with a constant noise figure and saturable power.

Abstract: Optical logic circuits are based on lazing semiconductor optical amplifiers, such as vertical lazing semiconductor optical amplifiers. For example, one or more VLSOAs with selected depletion thresholds are combined to form various optical logic devices.

Abstract: An optical add drop multiplexer (OADM) comprised of a plurality of lasing semiconductor optical amplifiers for performing the switching of optical signals from various inputs to outputs in the switching fabric of the OADM.

Abstract: Optical regenerators are disclosed, one of which includes a splitter having an input signal input, and first and second outputs, where the first output is connected to a first input of an optical flip-flop that also includes an output. A first OAND gate includes a first input connected to the output of the optical flip-flop, and also includes a second input and an output. A second OAND gate has a first input connected to the second output of the splitter, and includes a second input and an output. A variable oscillator having an input and an output is arranged so that the output is connected to the second input of the second OAND gate and to the second input of the first OAND gate. Finally, a feedback controller has an input connected to the second OAND gate output, and an output connected to the variable oscillator input.

Abstract: An optical 2R/3R regenerator is described. One or more LSOAs are used as part of the optical 2R/3R register.

Abstract: A multi-stage tunable gain optical amplifier device amplifies an optical signal by a gain amount which can be adjusted in one of the stages of the amplifier. The multi-stage amplifier includes at least two optical amplifier stages coupled in series, one of which is a tunable gain amplifier stage. The optical amplifier stages are characterized by a design parameter which varies from stage to stage. In a preferred embodiment, the design parameter includes a noise figure and a saturable power, with both parameters increasing as the optical signal propagates from stage to stage. As a result, the multi-stage tunable gain optical amplifier can achieve better noise performance and higher output power than a single stage optical amplifier with a constant noise figure and saturable power.

Abstract: A method and system for introducing optical delay. Using a tunable laser in combination with a group velocity dispersive element, laser tuning is used to create the desired amount of optical delay.