Bilayer graphene (BLG), composed of two graphene layers in a Bernal stacking configuration, is naturally a semi-metal. However, by applying a perpendicular electric field across the bilayer using top and bottom electrical gates, a bandgap is opened, transforming the system to a semiconducting one. This "gapped bilayer graphene" (gBLG) platform enables continuous adjustment of the bandgap energy with gate voltage, situating its optical transitions in the mid-infrared to terahertz spectral range. Near the band edge, electrons and holes form excitons with unusually large binding energies, causing these excitonic resonances to dominate the optical response. Since both the bandgap and the excitons can be electrically tuned, gBLG offers a versatile, gate-controlled medium for manipulating light and matter at long wavelengths. In our group, we explore how to understand and leverage this excitonic response for innovative mid-IR and THz optoelectronic functionalities.