Optical techniques can assess the heterogeneity and structural layers of biomaterial and implants. Such assessment can assist engineering of tissue patches and implants by assessing implant structure, monitoring the implant fabrication process, controlling the machining of the implant, and monitoring in vivo the body's host response to the implant. Optical scattering can quantify the granularity of a biomaterial on the scale of 0.1 - 10 micrometer. Optical coherence tomography can map heterogeneity on the scale of 2 - 20 micrometer. Optoacoustic imaging can image absorbing heterogeneities on the scale of 20 micrometer - 10 mm (or more). Diffusion optical tomography can image absorbing and scattering heterogeneities on the scale of 5 mm - 5 cm (or more). The opportunities for optical techniques in preparing biomaterials and implants are discussed.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.