Shinji Mino

160-Gb/s optical-time-division multiplexing with PPLN hybrid integrated planar lightwave circuit

160-Gb/s (20 Gb/s /spl times/ 8) optical time-division-multiplexing is demonstrated using a multiplexer based on periodically poled lithium niobate hybrid integrated planar lightwave circuits. With this multiplexer, eight 20-Gb/s signals are independently modulated and time division multiplexed all-optically. To confirm the quality of the multiplexed signal, it was demultiplexed and bit error rates were measured. The measured power penalties are less than 2.2 dB.

160-Gb/s OTDM transmission using integrated all-optical MUX/DEMUX with all-channel modulation and demultiplexing

This letter provides the first report of 160-Gb/s optical time-division-multiplexed transmission with all-channel independent modulation and all-channel simultaneous demultiplexing. By using a multiplexer and a demultiplexer based on periodically poled lithium niobate and semiconductor optical amplifier hybrid integrated planar lightwave circuits, 160-km transmission is successfully demonstrated.

Planar lightwave circuit platform with coplanar waveguide for opto-electronic hybrid integration

We propose a planar lightwave circuit (PLC) platform constructed on a silica-on-terraced-silicon (STS) substrate for opto-electronic hybrid integration. This platform consists of an embedded silica PLC region, a terraced silicon region for optical device assembly, and a high-speed electrical circuit region. In the electrical circuit region, the coplanar waveguides (CPW) are prepared on a thick-silica/silicon substrate. This structure reduces the propagation loss of the CPW drastically to 2.7 dB/cm at 10 GHz, because the loss tangent (tan /spl delta/) of the dielectric constants of silica is much smaller than that of silicon. In order to study the feasibility of this PLC-platform for multi-gigabit operation, we used it to fabricate an LD module in which an LD chip and LD-driver integrated circuits (IC) are assembled on the PLC-platform. A bit error rate measurement of this LD module in a 2.5 Gb/s NRZ showed that this platform is applicable to multi-gigabit optical signal processing.

Large-Capacity Compact Optical Buffer Based on InP Integrated Phased-Array Switch and Coiled Fiber Delay Lines

Optical buffering has been one of the major technical challenges in realizing optical packet switching (OPS) routers. While fiber-delay-line-based (FDL) buffers are the most practical and realistic solution to offer useful amount of capacity, the bulkiness of long FDLs and optical switches has been the main obstacle to practical implementation. This paper demonstrates a compact optical buffer with up to 750-ns capacity and 50-ns temporal resolution by using an InP integrated 1×16 optical phased-array switch and compact FDL module based on thin-cladding highly nonlinear fiber (HNLF). Owing to the high mode confinement inside HNLF, 15 fibers with the total length of 1.2 km are coiled onto a single bobbin with a coin-sized footprint without increasing the propagation loss. At the interface between the InP switch and FDLs, a pitch-converting silica planar-lightwave circuit chip is employed to achieve 16-port simultaneous uniform interconnection. Using the developed module, variable optical buffering experiment is demonstrated, where the packet intervals are expanded from 20 to 70 ns successfully.

High-speed 32-channel optical wavelength selector using PLC hybrid integration

We have developed a new high-speed 32-channel optical wavelength selector (OWS) with gate drivers using PLC hybrid integration. It has excellent characteristics consisting of a low insertion loss of 2.3 dB, a low cross talk of -46 dB and the error-free optical wavelength selection of 10-Gbit/s optical signal.

Novel flexible-format optical modulator with selectable combinations of carrier numbers and modulation levels based on silica-PLC and LiNbO 3 hybrid integration

We devised a novel flexible-format optical modulator that can optically select optimum sets of carrier numbers and modulation levels according to transmission conditions. The modulator with PLC-LN hybrid integration was successfully operated at 200 Gbps.

High-Speed Optical 1

We demonstrate a high-speed optical switch based on a generalized Mach-Zehnder interferometer with a hybrid configuration consisting of a silica-based planar lightwave circuit and lithium niobate phase shifters. The novel switch demonstrated here has one input and four output ports and a switching time of less than 0.1 mus, thanks to the fast response of the electrooptic phase shifters on the LN chip. The insertion loss and extinction ratio of the switch are 4.2 dB and more than 17 dB, respectively

\times

We investigated the propagation losses and the characteristic impedances Z/sub L/ of coplanar waveguides (CPWs) and microstrip lines (MSLs) on a planar lightwave circuit (PLC)-platform formed on a silica/silicon substrate. The loss of the CPWs was 2.7 dB/cm at 10 GHz on the PLC-platform with 30 /spl mu/m thick silica layer. Thus, a cm-order circuit of this CPW is difficult to fabricate in the 10 Gb/s module. This is because the silicon substrate has a large loss tangent (tan /spl delta/). On the other hand, the loss of the MSLs, where a ground plane shielded the high loss silicon substrate, could be improved to 0.9 dB/cm at 10 GHz with 30 /spl mu/m thick polyimide. These lower loss MSLs on a PLC-platform can be applied to module operation at 10 Gb/s. Furthermore they have the advantage that they are suitable for application to array device circuits or circuits in a module where several devices are integrated because unlike CPWs the ground planes are not divided by signal lines or DC bias lines. The structure of CPWs and MSLs on a PLC-platform with a Z/sub L/ of 50 /spl Omega/ was also studied in detail.

4 Switch Based on Generalized Mach–Zehnder Interferometer With Hybrid Configuration of Silica-Based PLC and Lithium Niobate Phase-Shifter Array

We devised an optical modulator with a high field-response linearity, which is suitable for a DAC-based multilevel coherent transmitter. An advantage over a conventional MZM in terms of the linearity-loss tradeoff was demonstrated.

High frequency electrical circuits on a planar lightwave circuit platform

We demonstrate a tunable optical dispersion compensator consisting of an arrayed-waveguide grating and a liquid crystal on silicon. We obtained a tuning range of ± 800 ps/nm with a bandwidth of 16 GHz.