1. Electro-Absorption Modulator Vertically Integrated on a VCSEL: Microstrip-Based High-Speed Electrical Injection on Top of a BCB Layer
- Author
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Aurélie Lecestre, Hugo Thienpont, Christophe Viallon, Ayad Ghannam, Guilhem Almuneau, Ludovic Marigo-Lombart, Alexandre Rumeau, Alexandre Arnoult, Krassimir Panajotov, Laurent Mazenq, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Équipe Microondes et Opto-microondes pour Systèmes de Télécommunications (LAAS-MOST), Service Instrumentation Conception Caractérisation (LAAS-I2C), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), 3DiS Technologies, Department of Applied Physics and Photonics [Brussels] (TONA), Vrije Universiteit Brussel (VUB), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Applied Physics and Photonics, and Brussels Photonics Team
- Subjects
Materials science ,Electro-absorption modulator ,02 engineering and technology ,VCSEL ,Microstrip ,Vertical-cavity surface-emitting laser ,[SPI.MAT]Engineering Sciences [physics]/Materials ,chemistry.chemical_compound ,020210 optoelectronics & photonics ,Benzocyclobutene ,High-speed modulation ,high-speed modulation ,0202 electrical engineering, electronic engineering, information engineering ,electro-absorption modulator ,Output impedance ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,BCB ,business.industry ,Coplanar waveguide ,Atomic and Molecular Physics, and Optics ,Electrical contacts ,chemistry ,Modulation ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,Optoelectronics ,business ,BENZOCYCLOBUTENE ,FABRICATION ,PASSIVATION ,FILMS - Abstract
International audience; Vertical-cavity surface-emitting lasers with vertically integrated electro-absorption modulators (EAM-VCSELs) potentially can reach higher modulation bandwidths than directly current-modulated VCSELs. The aforementioned device modulation capabilities are, however, currently restricted by their electrical contact parasitics. It, thus, becomes critical to optimize their access line to improve performance. In this paper, we numerically and experimentally demonstrate that a microstrip (MS) access line using a planarized benzocyclobutene (BCB) layer exhibits improved high-frequency characteristics compared to the coplanar waveguide (CPW) access line used to-date, since it reduces the losses induced by the doped substrates. We also use this opportunity to introduce an innovative technique for BCB layer planarization, which is not only compatible with the EAM-VCSEL double-mesa structure, but is also independent of the device pitch. The resulting BCB layer dielectric permittivity and losses are measured up to 100 GHz, and a side-by-side comparison of the electrical response of three-electrodes MS and CPW access lines is subsequently carried out. Finally, using the measured pad and access line RF responses and the EAM modulation characteristics, the devices with MS access are shown to be no longer limited by their electrode parasitics, but by the modulator internal impedance.
- Published
- 2019