GaSb-based integrated lasers and photodetectors on a silicon-on-insulator waveguide circuit for sensing applications in the shortwave infrared

We report our results on GaSb photodiodes and lasers integrated on a Silicon-On-Insulator waveguide circuit. The photodiodes operate at room temperature with 0.4A/W responsivity for grating-assisted coupling and >1 A/W for an evanescent design. On the other hand, integrated Fabry-Perot lasers operate in continuous wave at room temperature with a threshold current of 49.7mA

InGaAsSb/GaSb lasers and photodetectors integrated on a silicon-on-insulator waveguide circuit for spectroscopic applications

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

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

High-efficiency SOI fiber-to-chip grating couplers and low-loss waveguides for the short-wave infrared

We report on high-efficiency silicon-on-insulator (SOI) grating couplers and low-loss single-mode optical waveguides operating in a short-wave infrared. A -3.8 dB coupling efficiency from a standard single-mode fiber to an SOI waveguide at 2.1 mu m is obtained experimentally. Single-mode waveguide losses in the short-wave infrared below 0.6 dB/cm are reported