A system in an embodiment can comprise an optical assembly, an surface-plasmon-resonance (SPR) light source, and an SPR camera. The optical assembly can comprise a hemispherical prism comprising a top surface configured to support a SPR sensor; and a high numerical aperture (NA) lens located distal from the top surface of the hemispherical prism. The SPR light source can be configured to emit a light beam for SPR imaging. The SPR camera can be configured to capture an SPR image. The SPR sensor further can comprise a surface configured to contact a sample. The high NA lens can be configured to refract the light beam toward the hemispherical prism. The hemispherical prism can be configured to collimate the light beam, as refracted by the high NA lens, toward the SPR sensor. The high NA lens further can be configured to receive and refract the light beam toward the SPR camera, after the light beam is reflected by the surface of the SPR sensor. Other embodiments are disclosed.