A system and method for establishing optical communication between the depths of the biological tissue, optionally exceeding 1 cm, and the ambient environment with the use of an optical waveguide device that includes biodegradable material. The waveguide device is configured to deliver light from the outside into the biological tissue and/or vice versa. The light delivered from the biological tissue is informative about the status of the tissue. A specific waveguide device includes a mesh of biodegradable optical waveguides, is configured for insertion into the tissue, and does not require to be removed from the tissue after the irradiation of the tissue has been accomplished.
