Broadband Lateral Tapered Structures for Improved Bandwidth and Loss Characteristics for All-Optical Wavelength Converters Xuejin Yan, Joe Summers, Wei Wang, Marcelo Davanco, Wenbin Zhao, Milan Masanovic, Vikrant Lal, and Daniel Blumenthal Electrical and Computer Engineering University of California at Santa Barbara Good morning, my name is Xuejin Yan and My topic is

Summary of Work Objective: Develop building blocks to extend tuning range and decrease insertion loss of SOA XPM tunable wavelength converter to 30nm tuning range at 1.55m wavelength. Approach: Monolithically Integrate SOA wavelength converter with Mach-Zehnder structure with tunable laser using based-InP material. Major accomplishments: 1) Designed new type of broadband splitter/combiner for WC. 2) Active/passive structures have been designed for same structures. 2) Splitter loss was measured to be better than MMI and Y-splitter over a wavelength range of 100nm. 3) Active XGM was demonstrated using this design. 4) A TWC has been designed and preliminary measurements are being taken. 5) low reflection and low loss coupling techniques have been designed and fabricated: (i) a window design and (ii) a tapered mode converter Here is the summary of the work we did

Outline Mach-Zehnder SOA wavelength converter with new waveguide structure. The splitter with lateral tapers The vertical coupler at the interface of active to passive waveguide The mode-shape converter with lateral taper and InP windows XGM results (first stage of wavelength conversion) Tunable wavelength converter(WC with integrated tunable laser). The structure of the TWC Progress for TWC C. Future work Here is my outline,

The picture of WC Here is the picture of the wavelength converter( XPM and XGM )

Splitter and combiner Waveguide layer InP Substrate This is the structure of the splitter. The three waveguides are tapered laterally in the coupling region. The lower pictures are the simulation results of BPM.

Wavelength sensitivity of the splitter Its advantages are low loss and very low wavelength sensitive. This curve has shown its these characteristics.

The picture of the splitter

Near Field Image of Splitter Distance between two spots is 250 m

The spectrum of the splitter with integrated SOA

Active to passive vertical transformer Active layer InP etching stop layer Waveguide layer InP Substrate

The Vertical Coupler

InP window and mode-shape converter Lateral taper InP window InP Substrate

The Function of InP Window

Near Field Image of Splitter with 50mm InP Window

Gain Suppression of SOA Input light Output light

2.5GHz XGM eye diagram Probing wavelength =1560nm, pumping wavelength =1570nm.

5.0GHz XGM Eye Diagram Probing wavelength =1560nm, pumping wavelength =1570nm.

Progress for TWC SSG-DBR laser has been integrated into WC to reduce coupling loss Splitter dimensions have been increased to ease fabrication The first device of TWC has been fabricated

Wavelength Converter with Integrated SSG-DBR Laser

Future Work Measure and characterize the new TWC devices Optimize the processing and design of TWC Provide a high quality TWC device