We report a low-cost manufacturing approach for fabricating monolithic multi-wavelength sources for dense wavelength division multiplexing(DWDM)systems that offers high yield and eliminates crystal regrowth and select...We report a low-cost manufacturing approach for fabricating monolithic multi-wavelength sources for dense wavelength division multiplexing(DWDM)systems that offers high yield and eliminates crystal regrowth and selective area epitaxy steps that are essential in traditional fabrication methods.The source integrates an array of distributed feedback(DFB)lasers with a passive coupler and semiconductor optical amplifier(SOA).Ridge waveguide lasers with sampled Bragg side wall gratings have been integrated using quantum well intermixing to achieve a fully functional four-channel DWDM source with 0.8 nm wavelength spacing and residual errors<0.13 nm.The output power from the SOA is>10 mW per channel making the source suitable for use in passive optical networks(PONs).We have also investigated using multisection phase-shifted sampled gratings to both increase the effective grating coupling coefficient and precisely control the channel lasing wavelength spacing.An 8-channel DFB laser array with 100 GHz channel spacing was demonstrated using a sampled grating with twoπ-phase-shifted sections in each sampling period.The entire array was fabricated by only a single step of electron beam lithography.展开更多
Polarization control is at the heart of high-capacity data optical communication systems,such as polarizationdivision multiplexers and Stokes vector modulation transmitters.Despite passive polarization control being m...Polarization control is at the heart of high-capacity data optical communication systems,such as polarizationdivision multiplexers and Stokes vector modulation transmitters.Despite passive polarization control being mature,the realization of monolithically integrated polarization controllers and single longitudinal mode light sources,such as distributed-feedback(DFB)lasers,is of importance.In this research,we report an AlGaInAs multiple-quantum-well photonic integrated circuit device which can control the state of polarization of the output light source,consisting of a polarization mode converter(PMC),a differential phase shifter(DPS),and a sidewall grating DFB laser.We demonstrate an asymmetrical stepped-height ridge waveguide PMC to realize TE to TM polarization conversion and a symmetrical straight waveguide DPS to enable polarization rotation from approximately counterclockwise circular polarization to linear polarization.Based on the identical epitaxial layer scheme,all the PMC,DPS,and DFB lasers can be integrated monolithically using only a single step of metalorganic vapor-phase epitaxy and two steps of III-V material dry etching.For the DFB-PMC device,a high TE to TM polarization conversion efficiency(98.4%)over a wide range of DFB injection currents is reported at 1555 nm wavelength.For the DFB-PMC-DPS device,a nearly 60°rotation of the Stokes vector on the Poincarésphere was obtained with a range of bias voltage from 0 to-3.0 V at a laser drive current of 170 mA.展开更多
基金This work was supported by the U.K.Engineering and Physical Sciences Research Council(EP/R042578/1)and the National Science Foundation of China(61320106013).We would like to acknowledge the staff of the James Watt Nanofabrication Centre at the University of Glasgow for help in fabricatingthe devices.
文摘We report a low-cost manufacturing approach for fabricating monolithic multi-wavelength sources for dense wavelength division multiplexing(DWDM)systems that offers high yield and eliminates crystal regrowth and selective area epitaxy steps that are essential in traditional fabrication methods.The source integrates an array of distributed feedback(DFB)lasers with a passive coupler and semiconductor optical amplifier(SOA).Ridge waveguide lasers with sampled Bragg side wall gratings have been integrated using quantum well intermixing to achieve a fully functional four-channel DWDM source with 0.8 nm wavelength spacing and residual errors<0.13 nm.The output power from the SOA is>10 mW per channel making the source suitable for use in passive optical networks(PONs).We have also investigated using multisection phase-shifted sampled gratings to both increase the effective grating coupling coefficient and precisely control the channel lasing wavelength spacing.An 8-channel DFB laser array with 100 GHz channel spacing was demonstrated using a sampled grating with twoπ-phase-shifted sections in each sampling period.The entire array was fabricated by only a single step of electron beam lithography.
基金Engineering and Physical Sciences Research Council(EP/R042578/1)Chinese Ministry of Education Collaborative Project(B17023)。
文摘Polarization control is at the heart of high-capacity data optical communication systems,such as polarizationdivision multiplexers and Stokes vector modulation transmitters.Despite passive polarization control being mature,the realization of monolithically integrated polarization controllers and single longitudinal mode light sources,such as distributed-feedback(DFB)lasers,is of importance.In this research,we report an AlGaInAs multiple-quantum-well photonic integrated circuit device which can control the state of polarization of the output light source,consisting of a polarization mode converter(PMC),a differential phase shifter(DPS),and a sidewall grating DFB laser.We demonstrate an asymmetrical stepped-height ridge waveguide PMC to realize TE to TM polarization conversion and a symmetrical straight waveguide DPS to enable polarization rotation from approximately counterclockwise circular polarization to linear polarization.Based on the identical epitaxial layer scheme,all the PMC,DPS,and DFB lasers can be integrated monolithically using only a single step of metalorganic vapor-phase epitaxy and two steps of III-V material dry etching.For the DFB-PMC device,a high TE to TM polarization conversion efficiency(98.4%)over a wide range of DFB injection currents is reported at 1555 nm wavelength.For the DFB-PMC-DPS device,a nearly 60°rotation of the Stokes vector on the Poincarésphere was obtained with a range of bias voltage from 0 to-3.0 V at a laser drive current of 170 mA.
