Diffuse optical imaging is a medical imaging modality which uses near infrared light to generate images of the body. The technique measures the absorption of haemoglobin, and relies on the absorption spectrum of haemoglobin varing with its oxygenation status.

Typical applications include rapid 2D optical topographic imaging of the evoked response following brain activity and tomographic reconstruction of an entire 3D volume of tissue to diagnose breast cancer or neonatal brain haemorrhage.