Continuously Tunable, Polarization Stable SWG MEMS VCSELs at 1.55 \mu

• Published in: IEEE photonics technology letters 2013-05, Vol.25 (9), p.841-843
• Main Authors: Grundl, Tobias, Zogal, K., Debernardi, P., Muller, M., Grasse, C., Geiger, K., Meyer, R., Bohm, G., Amann, M-C, Kuppers, F., Meissner, P.
• Format: Article
• Language: English
• Subjects: Distributed Bragg reflectors; Etching; Gratings; Holography; InP; micro-electro-mechanical-system (MEMS); Micromechanical devices; subwavelength grating; tunable; Tuning; Vertical cavity surface emitting lasers; vertical-cavity-surface-emitting laser (VCSEL)
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/LPT.2013.2250276

We present polarization stable, tunable long-wavelength vertical-cavity-surface-emitting lasers (VCSELs) at 1.55 μm based on InP. The tuning is accomplished by a two-chip membrane mounting technique denoted as bulk-micro-machining. The membrane consists of a GaAs-based distributed Bragg reflector and represents the top mirror. By its electro thermal actuation, cavity tuning occurs. This results in a continuous wavelength shift. Polarization stability is achieved by an implemented semiconductor/air subwavelength grating (SWG) written in the top-most layers of the membrane facing the VCSEL eye after mounting process. The SWG integration is realized by a combination of holographic lithography, barrel, and reactive ion etching. The manufactured micro-electro-mechanical-system SWG-VCSELs show a continuous, polarization stable wavelength tuning of ~ 25 nm with a peak optical power of 4 mW fiber-coupled in an MMF and thresholds of 3-3.5 mA.