Hee-Kyung Sung

Multiwavelength Lasers for WDM-PON Optical Line Terminal Source by Silica Planar Lightwave Circuit Hybrid Integration

We have demonstrated a very compact eight-channel 200-GHz-spacing multiwavelength laser (MWL) module for the optical line terminal source of wavelength-division-multiplexing passive optical network. The wavelength shift of MWLs and external cavity lasers from the ITU grid was within +0.14 nm for eight channels, which was well matched to the target wavelength shift of less than plusmn0.2 nm. The oscillation characteristics of our MWL module are better than those of conventional MWLs with hybrid integration.

Board-to-board optical interconnection system using optical slots

A practical optical backplane system was prepared with transmitter-receiver processing boards and an optical backplane made of polymeric-waveguide-embedded optical printed-circuit boards. As connection components between the transmitter-receiver processing boards and backplane board, optical slots were used to enable easy and repeatable insertion and extraction of the boards with micrometer precision. We report an 8-Gb/s data transmission between transmitter processing board and optical backplane.

A novel method for fabrication of a PLC platform for hybrid integration of an optical module by passive alignment

A novel fabrication method and structure of a planar lightwave circuit (PLC) platform for hybrid integration of an optical module by passive alignment technology is presented. Precise formation of V-grooves in the PLC platform can be easily obtained by the proposed process. The passive alignments of optical elements, including optical fiber, are achieved in one-mask. LD modules were implemented by the proposed method.

Experimental demonstration of 10?Gbit?s transmission with an optical backplane system using optical slots

A practical optical backplane system was prepared with transmitter-receiver processing boards and an optical backplane made from polymeric-waveguide-embedded optical printed-circuit boards. Optical slots were used as connection components between the transmitter-receiver processing boards and the backplane board to permit easy and repeatable insertion and extraction of the boards with micrometer precision. We report 10 Gbit/s data transmission between an optical backplane and the transmitter-receiver processing boards.

Fabrication of a TFF-Attached WDM-Type Triplex Transceiver Module Using Silica PLC Hybrid Integration Technology

An optical triplex transceiver (TRx) module, which consists of thin-film filter (TFF)-attached wavelength-division multiplexer (WDM) and photodiode (PD) carriers, has been fabricated using a silica planar lightwave circuit (PLC) hybrid integration technology. Two types of TFFs were attached to a diced sidewall of a silica-terraced PLC platform to realize the TFF-attached WDM. The PD carriers with a 45deg mirror, on which receiving surface-illuminated PDs were bonded, were assembled with the PLC platform to form receiver (Rx) parts. As the main performances of the packaged TRx module, a very clear transmitter (Tx) eye pattern and minimum Rx sensitivity of -25.7 dBm were obtained under a 1.25-Gb/s Tx-Rx operation for digital applications. For an analog Rx application, a module responsivity of about 0.8 A/W was achieved, and a second-order intermodulation distortion value of less than -70 dBc at an optical modulation index of 40% was obtained under a two-tone test of 400 and 450 MHz

200 GHz-spacing 8-channel multi-wavelength lasers for WDM-PON optical line terminal sources.

We have fabricated modules of 8-channel multi-wavelength lasers (MWLs) with a wavelength separation of 200 GHz for the wavelength division multiplexed-passive optical network (WDM-PON) optical line terminal sources. The variation in the output power is minimized by inserting silicone between the superluminescent diode (SLD) and the silica waveguide. The wavelength shift of each channel is less than 0.21 nm from the ITU grid and can be controlled in the range of 0.36 nm without any reductions of the output power by a tuning heater. MWLs operated successfully in the direct modulation for 1.25 Gbit/s transmissions over 20 km.

1.25-Gb/s bidirectional transceiver module using 1.5%-/spl Delta/ silica directional coupler-type WDM

A 1.5%-/spl Delta/ silica directional coupler-type wavelength-division multiplexer dividing 1310/1550-nm wavelength bands was used to develop a bidirectional optical transceiver module. The active devices such as a spot-size converted Fabry-Pe/spl acute/rot laser diode and waveguide photodetectors were hybridly integrated on a silica-terraced planar lightwave circuit platform. As main performances of the module, the clear eye pattern and the minimum receiver sensitivity of -25.5 dBm were obtained under the full duplex operation at 1.25 Gb/s without a severe power penalty.

Wavelength-Tuning of Hybrid Integrated Multiwavelength Lasers Using a Heater

We propose and demonstrate very compact multiwavelength lasers (MWLs) with a novel configuration designed to remove the mode hopping in the modulation region and separate the wavelength-tuning of each channel for cost-effective optical line termination sources in the wavelength-division-multiplexing passive optical network. The mode hopping of MWLs in the modulation region was eliminated by wavelength trimming using a tuning heater. The MWLs operated successfully in direct modulation for 1.25-Gb/s transmission over 20 km.

A two-step etching technique for silica terraces in the PLC hybrid integration

Two-step etching, after the full processes of a silica waveguide, was performed to fabricate a silica-terraced planar lightwave circuit platform for the hybrid integration of optoelectronic devices. Spot-size converted distributed feedback laser diodes (SSC DFB LDs) were flip-chip bonded on silica terraces with the height accuracy of less than 1 /spl mu/m, and the resultant coupling loss between the SSC DFB LD and the silica waveguide was about 3.78 dB. The light-current curve of the LD flip-chip bonded on the platform showed the almost linear increase of the output power without any saturation.

Fabrication of WDM-PON OLT Source using External Cavity Laser

A very compact 16-channel 200 GHz-spacing transmitter module was fabricated for wavelength division multiplexing-passive optical network (WDM-PON) optical line termination (OLT) source. The transmitters are composed of reflection gratings and hybrid integrated superluminescent laser diodes (SLD) to construct 16-channel external cavity lasers (ECLs) on the planar lightwave circuit (PLC) chip.