Maura Raburn

All-optical flip-flop multimode interference bistable laser diode

All-optical flip-flop operation of multimode interference bistable laser diodes (MMI-BLDs) was experimentally demonstrated for the first time. The MMI-BLD was prepared with a conventional ridge waveguide laser diode fabrication procedure, suitable for photonic integrated circuits. Bistable switching via two-mode bistability was obtained with approximately 0-dBm input powers due to cross-gain saturation and the saturable absorbers. Bit-length conversion was successfully obtained with noninverted and inverted outputs. This device will be useful in future photonic systems requiring all-optical latching functions such as optical memory, self-routing, and further optical signal processing.

3-D photonic circuit technology

Vertically coupled, wafer-bonded III-V semiconductor waveguide devices provide a means to obtain more powerful, compact photonic integrated circuits and allow for the combination of different materials onto a single chip. Various switching, filtering, multiplexing, and beam splitting devices in the InP-InGaAsP and GaAs-AlGaAs systems for signals in the 1550-nm range have been realized. An investigation of optimal optical add-drop multiplexer waveguide layout shapes has been performed through integration of the coupled-mode Riccati equation, providing potential sidelobe levels of less than -32 dB and filter bandwidths over 20% narrower than those of previous devices. Effects of nonideal processing conditions on filter performance are analyzed as well.

All-optical switching of 40 Gb/s packets by MMI-BLD optical label memory

We demonstrated all-optical label storing and switching for 40 Gb/s optical packets by using all-optical signal processing of multimode interference bistable laser diode optical flip-flops. The stored optical labels in the optical flip-flop controlled an all-optical switch to forward the injected optical packets. The 40 Gb/s optical packets were successfully switched in the all-optical scheme with 11-dB extinction ratio. Error-free operation for the output packets from the switch was also obtained with 1.3-dB power penalty. The presented all-optical packet switching has the advantages of ultrafast switching and transparency of data rate and format, suitable for the future optical networks.

10 channel, 45.6Gb/s per channel, polarization multiplexed DQPSK InP receiver photonic integrated circuit

We demonstrate a 10 wavelength, monolithically integrated, polarization multiplexed, InP DQPSK receiver operating at 45.6 Gbit/s per wavelength.

Integrable multimode interference distributed Bragg reflector laser all-optical flip-flops

A novel fully integrable all-optical flip-flop has been created using distributed Bragg reflector multimode interference bistable laser diodes. The single metal-organic vapor phase epitaxy regrowth offset quantum well structure active/passive integrated flip-flop lases in single mode at 1554 nm and is compatible with standard fabrication methods of InP photonic integrated circuits (PICs). All-optical reset switching through cross-gain saturation was demonstrated over a 52-nm range, at 1522-1574 nm. An optical set has been achieved with -3 dBm and optical reset with less than -5-dBm external light injection. The flip-flop will be useful for integration in PICs of future photonic systems for self-routing and optical memories or buffers

Dynamic operation of all-optical flip-flops with distributed bragg reflectors for self-routing of 10-Gbit/s optical packets

We present the dynamic all-optical flip-flop (AOFF) operation of a multimode interference (MMI) bistable laser diode (BLD) with distributed Bragg reflector (DBR) mirrors, which allow single-mode lasing and on-chip integration with other waveguide devices. The DBR-MMI-BLD has been operated by 10-ns-wide optical set/reset pulse, resulting in 320 ps rising time and 470 ps falling time. Self-routing of 10 Gbit/s optical packets has also been demonstrated using the Mach–Zehnder interferometer (MZI) semiconductor optical amplifier (SOA) all-optical switch driven by the DBR-MMI-BLD AOFF. The 10 Gbit/s optical packets were switched in the optical domain by cross-phase modulation of the SOA. The extinction ratio of the all-optical switch was 8 dB, and an error-free operation was obtained with 1.8 dB power penalty.

All-optical packet switching by MMI-BLD optical flip-flop

We demonstrated novel all-optical packet switching using all-optical flip-flop multimode interference bistable laser diodes and all-optical Mach-Zehnder interferometer switches. Error-free operation for output 10-Gb/s optical packets from the switch was obtained with no power penalty.

Double-bonded InP-InGaAsP vertical coupler 1:8 beam splitter

A novel three-layer double-bonded InP-InGaAsP waveguide vertical coupler 1:8 beam splitter is demonstrated. The strongly coupled waveguides allow a 583-/spl mu/m device length, more than 100 times shorter than that of the equivalent horizontal coupler. The device illustrates the use of multiple vertical-layer optical interconnects for three-dimensional routing of optical signals.

InP-InGaAsP wafer-bonded vertically coupled X-crossing multiple channel optical add-drop multiplexer

A vertically coupled InP-InGaAsP crossed waveguide optical add-drop multiplexer has been realized through the use of wafer bonding. Designed for signals in the 1550-nm range, this novel device requires only a single epitaxial growth and illustrates the use of vertical optical interconnects for the three dimensional routing of optical signals. To our knowledge, it is also one of the first optical vertically coupled devices with no horizontally coupled counterpart.

MMI-BLD optical flip-flop for all-optical packet switching

We have demonstrated all-optical packet switching, in which an MMI-BLD optical flip-flop worked as a label memory. The optical flip-flop allowed self-routing of multiple-wavelength packets with 338-ps switching time and 14-dB on-off ratio.