PLC Platform Research Articles

Reduction of insertion loss of thin film filters embedded in PLC platforms

We propose and experimentally demonstrate a method of reducing insertion loss of a thin-film-filter-embedded planar-lightwave-circuit platform for a triplexer transceiver module. Significant loss reduction was achieved by adding horn waveguide elements at the interfaces between the thin film filter and the output-port (transmission and reflection) waveguides.

PLC platform for bidirectional transceiver with wide multimode output waveguide to receiver

We present a new configuration of a thin-film-filter (TFF)-embedded planar-light-circuit platform for a bidirectional transceiver module to enhance a tolerance of the insertion loss to the positional deviation of the TFF, by using a wide multimode waveguide structure that guides a reflected light from the TFF to a photoreceiver. It is experimentally shown that the new scheme has a merit in a high tolerance to the positional deviation of the TFF, and that it maintains a considerably high optical isolation by a proper arrangement of waveguides.

A29: Software design of communication tasks in Grafcet

Grafcet is widely applied on many stages of a software life-cycle of real-time control systems. As a kind of STD (State Transition Diagram) it could be used for defining the behavior model at the system modeling stage. The Graftec as a programming language can also be employed at software development for embedded systems. In the paper is discussed the practical use of the Graftec in design the communication infrastructure of distributed control systems based on PLC platforms. In many software development systems Graftec is one of the five basic programming languages. The communication tasks are usually run concurrently to the other control jobs. This feature can be easily modeled and implemented in Graftec. Effective sharing the common resource – the serial bus through many communication nodes need persistent monitoring of the busy state of the bus. Performing communication tasks with the different frequency of service requests or occasionally upon appearance a certain event (e.g. malfunction) need monitoring of the time flow (time dependent control). The two above mentioned types of control can be easy implemented in Graftec algorithms. They are presented in the case study of the computer network combined with PCD2 PLCs linked with the serial bus RS485 and S-Bus protocol.

Dispersion resulting from wide passband shape in 50-GHz-spaced wavelength router

We report dispersions resulting from a slot device (SD) in silica-based arrayed-waveguide grating (AWG). A SD is used to produce flattened passbands and we show the dependence on the bandwidth, the crosstalk, the ripple, and the chromatic dispersion (CD) of the passband in the presence of such a device. A comparison with other known techniques is also given. The device has been developed on a high index silica-based PLC platform but can be implemented on higher index contrast platforms.

Hybrid Integrated Microphotonics and It's Applications

AbstractHybrid Integration of passive and opto-electronic devices is emerging as a key technology of optical component, because it can increase functionality and reliability of optical device module, lowers the packaging cost and enables automated manufacturing. Main applications of hybrid integrated microphotonic devices are FTTH system and metro access network.There are various technical issues in hybrid integration modules. It requires connecting an active device to a passive waveguide. The embedded functional devices such as grating, coupler, switch and filter are essential elements to improve optical performance of integrated devices. The package solution for low cost and small size is also required.We have developed SSC LD(Spot Size Converted Laser Diode) and RMF PD(Reflection Mirror Facet Photo Diode) for connecting to planar waveguide. Simple and cost-effective silica PLC platform with terraced-silica, PLC grating and coupler have been developed. Using these technologies, we have made bi-directional diplexer, triplexer and ECL(External Cavity Laser).

ASPECT - Advanced Control Algorithms on Industrial Controllers

The advanced control system for control of nonlinear, slowly time variant and delayed processes is described in the paper. The proposed control system performs automatic tuning of fuzzy gain-scheduling controller parameters. The parameters are tuned according to a non-linear process model, which is identified by performing simple experiments on the actual process. The proposed control system (ASPECT) is implemented as a software product and currently runs on several PLC platforms.

Compact PLC-based optical transceiver module with automatic tunable filter for multi-rate applications

A full-duplex, simultaneous operation, multi-rate optical transceiver module for flexible optical access network systems has been fabricated. Based on a PLC platform, the module is compact, highly sensitive, and supports multi-rate operation because it offers automatic transimpedance gain and band-pass filtering. This module will realise economical optical access network systems.

An Etch-Stop Technique Using Cr2O3 Thin Film and Its Application to Silica PLC Platform Fabrication

Using Cr2O3 thin film, we developed a novel etch-stop technique for the protection of silicon surface morphology during deep ion coupled plasma etching of silica layers. With this technique we were able to etch a silica trench with a depth of over 20 µm without any damage to the exposed silicon terrace surface. This technique should be well applicable to fabricating silica planar lightwave circuit platforms for opto-electronic hybrid integration.

100-GHz spacing eight-channel light source integrated with gratings and LDs on PLC platform

The authors successfully fabricate a 100-GHz spacing eight-channel light source integrated with gratings and laser diodes on a planar lightwave circuit platform. They obtain mode-hopping free-single mode oscillations, precisely controlled wavelengths, and sufficient output power of more than 1.5 mW at 80 mA.

A compact optical wavelength selector composed of arrayed-waveguide gratings and an optical gate array integrated on a single PLC platform

We developed a compact 16-ch optical wavelength selector (OWS). Our OWS is composed of two arrayed-waveguide gratings (AWG's) and an optical gate array (OGA) integrated on a single PLC platform by using the hybrid integration technique. We successfully obtained lossless operation with an extinction ratio of better than -45 dB for all wavelength channels. We also obtained a switching time of less than 1 ns. These excellent characteristics are the same as those of a previously reported OWS fabricated using PLC-PLC direct attachment.

Dynamic response of high-speed wavelength selector using hybrid integrated four-channel SS-SOA gate array on PLC platform

The dynamic response of a high-speed wavelength selector using a fully packaged four-channel semiconductor optical amplifier gate array on a PLC platform is reported. Ultra-wideband (1530 – 1600 nm) operation was successfully demonstrated. The gating time was sufficiently fast at 1 ns. The electrical interference between the channels was negligible.

Passively aligned hybrid WDM module integrated with spot-size converter integrated laser diode and waveguide photodiode on PLC platform for fibre-to-the-home

A low cost and high performance hybrid WDM module assembled by passive alignment has been developed for FTTH systems. High coupling efficiency of a spot-size converter integrated laser diode to a PLC waveguide, which facilitates mass production of the module, is achieved. A minimum optical received power of -37 dBm for a 50 Mbit/s burst signal is also achieved

Filter-embedded wavelength-division multiplexer for hybrid-integrated transceiver based on silica-based PLC

A thin film filter-embedded wavelength-division multiplexer is designed for a hybrid-integrated WDM transceiver based on a silica-based PLC platform. A compact multiplexer with a low insertion loss of 1.1 dB and a low crosstalk of <-50 dB is successfully fabricated.

Application of planar lightwave circuit platform to hybrid integrated optical WDM transmitter/receiver module

The authors have fabricated an optical WDM module with a simple configuration using a PLC platform together with a spot-size converted LD (SS-LD) and a waveguide PD (WG-PD). Since the module can be formed simply by flip-chip bonding of the SS-LD and the WG-PD, this configuration reduces the number of components, and thus helps achieve a cost reduction.

Optoelectronic hybrid integrated laser diode module using planar lightwave circuit platform

A planar lightwave circuit platform (PLC platform) for optoelectronic hybrid integration has been developed. This platform is a silica-on-terraced-silicon (STS) structure which consists of a silica PLC, silicon terraces for device assembly and high-speed electrical circuits. This PLC platform has been successfully applied to a 2.5 Gbit/s laser diode (LD) module. >