VCSEL Techniques for Wavelength-Multiplexed Optical Interconnects
Licentiate thesis, 2019
Capacity beyond the limits of current technologies is expected by also exploring the wavelength dimension, referred to as wavelength division multiplexing (WDM). This calls for the development of high-speed VCSELs at multiple wavelengths. To also enable the very small footprint transceivers and high bandwidth density needed as transceivers move closer to the switch AISC, the multiple wavelength VCSELs should be in a monolithic array. This requires a VCSEL technology where the wavelength of individual VCSELs can be precisely set in a post-growth fabrication process. As an integration platform for multiplexing and fiber coupling we envision a photonic circuit on Si with Si3N4 waveguides and grating couplers for VCSEL integration. With such waveguides being single mode and the grating couplers being polarization sensitive, the VCSELs in the array should be single transverse and polarization mode, in addition to having a high modulation bandwidth.
In this thesis, an intra-cavity phase tuning technique, based on an Ar ion-beam etching process with sub-nm precision, is demonstrated for setting the resonance wavelength of VCSEL resonators with <2 nm precision in the wavelength range 1040-1070 nm. Single transverse and polarization mode VCSELs with a record output power of 6 mW are also demonstrated. Suppression of higher order transverse modes and the orthogonal polarization state is achieved by etching a shallow mode filter in the surface of the VCSEL.
silicon photonic integration
vertical-cavity surface-emitting laser
transverse and polarization mode filter
distributed Bragg reflector.
Chalmers, Microtechnology and Nanoscience (MC2), Photonics
Precise setting of micro-cavity resonance wavelength by dry etching
Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics,; Vol. 37(2019)
High-power single transverse and polarization mode VCSEL for silicon photonics integration
Optics Express,; Vol. 27(2019)p. 18892-18899
Atom and Molecular Physics and Optics
Other Physics Topics
Other Electrical Engineering, Electronic Engineering, Information Engineering
Chalmers University of Technology
Kollektorn, lecture room, Kemivägen 9, MC2-huset
Opponent: Dr. Josip Vukusic from the THz and Millimeter Wave Laboratory