Akademik Veri Yönetim Sistemi
Measurement Science and Technology, cilt.36, sa.8, 2025 (SCI-Expanded, Scopus)
This work presents the design of a complementary metal oxide semiconductor (CMOS) compatible biosensing device that incorporates all necessary optical components, including the light source, on the silicon (Si) chip. The design includes a room-temperature, strained-germanium based laser to act as the light source, a germanium (Ge) waveguide to laterally guide the lasing output, and a Ge-based slot waveguide as the sensing region to sense the analyte filling the slot. Three-dimensional finite difference time domain simulation results demonstrate that the proposed design is capable of guiding up to 90% of the lasing output to the slot region through the Ge waveguide, and the transmittance of the light through the slot highly depends on the refractive index of the specimen filling it. The light intensity transmitted to the exit of the slot is observed to decrease by 30% when the specimen filling the slot is changed from healthy blood sample into cancerous blood sample. The difference in the transmittance is increased to 37% utilizing three parallel slots rather than a single slot even for the unoptimized design. Our results demonstrate that the structure we propose allows to distinguish the blood sample with cancerous cell from the healthy blood sample through a lateral transmission measurement. Our proposed design can be fabricated using standard Si microfabrication tools, including liquid phase epitaxy, making it ideal for mass production, which paves the way for the development of compact, cheap and disposable Ge-based lab-on-a-chip biosensors.