A biochip device includes a stratified structure, a light coupler, and an optofluidic portion. The stratified structure includes a top layer having a refractive index n1, a bottom layer having a refractive index n3, and an intermediate layer between the top and bottom layers having a refractive index n2. The light coupler optically couples a light source and the top layer to generate waves that are guided in a plurality of directions inside the top layer. The optofluidic portion is supported on a surface of the top layer and includes a hybridizing chamber containing a hybridizing solution and pads supported on the surface of the top layer and situated within the hybridizing chamber. Probe molecules are deposited on the pads. The refractive index n2 of the intermediate layer is greater than or equal to a highest index of refraction of the hybridizing chamber and the hybridizing solution.