Systems, methods, and apparatuses for providing on-board electromagnetic radiation sensing using beam splitting in a radiation sensing apparatus. The radiation sensing apparatuses can include a micro-mirror chip including a plurality of light reflecting surfaces. The apparatuses can also include an image sensor including an imaging surface. The apparatuses can also include a beamsplitter unit located between the micro-mirror chip and the image sensor. The beamsplitter unit can include a beamsplitter that includes a partially-reflective surface that is oblique to the imaging surface and the micro-mirror chip. The apparatuses can also include an enclosure configured to enclose at least the beamsplitter and a light source. With the apparatuses, the light source can be attached to a printed circuit board (PCB). Also, the enclosure can include an inner surface that has an angled reflective surface that is configured to reflect light from the light source in a direction towards the beamsplitter.