Payman Samadi

Tunable Lattice-Form Mach–Zehnder Interferometer for Arbitrary Binary Code Generation at 40 GHz

We use the direct temporal domain approach to design spectrally periodic optical filters for pulse repetition rate multiplication (PRRM) with envelope shaping. In particular, we demonstrate a tunable lattice-form Mach-Zehnder interferometer using Silica-based planar lightwave circuit (PLC) for arbitrary 4-bit binary amplitude code generation at 40 GHz and to increase the repetition rate of a 10 GHz input pulse train to 20 GHz or 40 GHz. In addition to PRRM and envelope shaping, the device also has the capability of arbitrary phase coding.

Generating 4

We demonstrate a tunable pulse repetition rate multiplier using a silica-based planar lightwave circuit (PLC). The PLC is a six-stage lattice-form Mach-Zehnder interferometer which can be tuned thermally to generate 20- and 40-GHz output pulse trains from a 10-GHz input. We use a nonlinear optical loop mirror as a wavelength converter to perform intensity-to-field conversion to eliminate pulse-to-pulse phase fluctuations in the higher-rate output pulse trains. Moreover, we use wavelength multicasting (simultaneous wavelength conversion) to generate multiple pulse trains (4 × 20 GHz and 4 × 40 GHz in the example shown here) from a single 10-GHz input.

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We demonstrate a tunable planar lightwave circuit for arbitrary 4-bit binary code generation at 40 GHz. The device is a 6-stage lattice-form Mach-Zehnder interferometer fabricated in silica-on-silicon technology.

20 GHz and 4

We demonstrate reconfigurable demultiplexing of arbitrary single or multiple 10 Gb/s tributary channels from a higher rate 40 Gb/s data signal using a programmable planar lightwave circuit (PLC) and four-wave mixing (FWM). The PLC is a thermally tunable six-stage lattice-form Mach-Zehnder interferometer fabricated in silica-on-silicon. We present results for optical time-division-multiplexing (OTDM) demultiplexing of both return-to-zero on-off keying (RZ-OOK) and differential phase-shift-keying (RZ-DPSK) data.

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The optimization of a 2×2 silica-on-silicon Mach-Zehnder interferometer (MZI) thermo-optic switch is presented. The device consists of 2 multimode interference (MMI) couplers as splitter and combiner with metal heater strips for phase control. The switching characteristics of the devices have been examined in detail as a function of several parameters. The electrical power consumption of the switch has been reduced by a factor of 2 by etching trenches alongside the waveguide heaters located on the arms of the MZI, and the polarization dependent loss has been controlled and reduced through adjustment of top cladding properties. The effect on the response time of the switch of these design changes has been investigated. Detailed characterization of the devices will be presented, and trade-offs in optimization discussed. Incorporation of these device elements into increasingly complex components for new applications in optical signal processing will be demonstrated.

40 GHz Pulse Trains From a Single 10-GHz Mode-Locked Laser Using a Tunable Planar Lightwave Circuit

We demonstrate the generation of 20 GHz and 40 GHz pulse trains using a tunable planar lightwave circuit (PLC) and nonlinear wavelength conversion. The PLC is a 6-stage lattice-form Mach-Zehnder interferometer fabricated in silica-on-silicon technology.

Tunable 6-stage lattice-form Mach-Zehnder interferometer for arbitrary binary code generation at 40 GHz

We experimentally demonstrate reconfigurable switching of four 10-Gb/s tributary channels of 40-Gb/s data using a programmable planar lightwave circuit and nonlinear wavelength conversion. Our device is a silica-on-silicon based 6-stage lattice-form Mach-Zehnder interferometer.

Reconfigurable OTDM Demultiplexing Using FWM in Highly Nonlinear Fiber and a Tunable Planar Lightwave Circuit

We demonstrate photonically-assisted generation of arbitrary RF waveforms with a bandwidth from 20-80 GHz using a reconfigurable silica-based planar lightwave circuit.

Thermo-optic silica PLC devices for applications in high speed optical signal processing

The development of silica planar lightwave circuits (PLCs) employing multiple phase-shifting elements to achieve optical signal processing is presented. Thermo-optic switching in Mach Zehnder interferometer (MZI) structures has been demonstrated with typical switching powers of 250-300 mW. 6-loop lattice-form MZI devices designed with specific filter responses have been fabricated, packaged, and tested. 10 GHz to 40 GHz pulse repetition rate multiplication has been achieved, and the tunability of the 6 phase control elements allows the generation of arbitrary 4-bit binary code patterns. Further improvements in complexity, power consumption, loss, and polarization sensitivity in these devices are discussed.