Heterogeneous GaSb/SOI mid-infrared photonic integrated circuits for spectroscopic applications

N. Hattasan (1) , Laurent Cerutti (2, 3) , Jean-Baptiste Rodriguez (2, 3) , Eric Tournié (2, 3) , Dries van Thourhout (1) , Günther Roelkens (1)

1 INTEC - Department of Information Technology
2 IES - Institut d’Electronique et des Systèmes
3 NANOMIR - Composants à Nanostructure pour le moyen infrarouge

Mid-infrared spectroscopy has gained significant importance in recent years as a detection technique for substances that absorb in this spectral region. Traditionally, a spectroscopic system consists of bulky equipment which is difficult to handle and incurs high cost. An integrated spectroscopic system would eliminate these disadvantages. GaSb-based active opto-electronic devices allow realizing mid-infrared light sources and detectors in the 2-3 mu m wavelength range for such integrated systems. Silicon photonics, based on Silicon-on-Insulator (SOI) waveguide circuits, on the other hand, is a well established technology based on high refractive index contrast waveguides, enabling ultra-compact passive integrated photonic circuits. Moreover, SOI waveguide circuit processing is compatible with CMOS processes. Hence, the integration of GaSb-based active devices onto SOI passive waveguide circuits potentially allows highly compact spectroscopic systems with a large degree of freedom in passive device design to improve the system performance. This approach has a high potential for several applications, e. g. an implantable glucose level monitor and gas sensing devices. In this paper, we report our work on the integration of GaSb-based epitaxy onto SOI waveguide circuits. The heterogeneous integration is based on an epitaxial layer transfer process using the polymer divinylsiloxane-benzocyclobutene (DVS-BCB) as a bonding agent. The process is performed by transferring the epitaxial layer to an SOI waveguide circuit wafer through a die-to-wafer bonding process. With this approach, a bonding layer of 150 nm thickness is easily achievable. We also report our results on the integration of waveguide-based GaSb p-i-n photodetectors coupled to SOI waveguide circuits using evanescent coupling, which show a responsivity higher than 0.4A/W. The design of active and passive structures and the overall fabrication process will also be discussed.

Domaines: Optique / photonique

N. Hattasan, Laurent Cerutti, Jean-Baptiste Rodriguez, Eric Tournié, Dries van Thourhout, et al.. Heterogeneous GaSb/SOI mid-infrared photonic integrated circuits for spectroscopic applications. Conference on Quantum Sensing and Nanophotonic Devices VIII, Jan 2011, San Francisco, CA, United States. pp.79451K, ⟨10.1117/12.874659⟩. ⟨hal-00641358⟩