An apparatus, comprising: a waveguiding first arrangement which is configured to provide at least one electromagnetic radiation; a configuration which is configured to receive and split the at least one electromagnetic radiation into a first radiation and a second radiation; a waveguiding second arrangement (120, 202, 208) which includes a first waveguide and a second waveguide (120, 202), wherein the first waveguide is configured to receive the first radiation, and the second waveguide (120, 202) is configured to receive the second radiation; a fiber coupler arrangement (316, 416); and a rotary junction (318, 418) coupled to the fiber coupler arrangement (316, 416); wherein the waveguiding first arrangement, the waveguiding second arrangement (202, 208), and the configuration are housed in a probe (320, 424), the waveguiding first arrangement comprising a first waveguide and a second waveguide, wherein the first waveguide is a core of an optical fiber, said fiber comprising at least two claddings, and the second waveguide is an inner cladding of the optical fiber; wherein the first waveguide of the waveguiding second arrangement (120, 202, 208) is a core of a first optical fiber and the second waveguide (120, 202) of the waveguiding second arrangement (120, 202, 208) is an optical fibre; wherein the configuration comprises an optics arrangement (106, 116) provided at the end of the waveguiding second arrangement (120, 202. 208); and wherein the first radiation is based on radiation from an OCT radiation source (302, 402) and the second radiation is based on radiation from a diffuse spectroscopy light source both of which are configured to illuminate at least one structure; wherein, the optics arrangement (106, 116) is configured to receive the first and second radiations from the at least one structure; wherein, the first radiation is provided to the first waveguide of the waveguiding first arrangement and the second radiation is provided to the second waveguide of the waveguiding first arrangement; and wherein, the fiber coupler arrangement (316, 416) is configured to extract the second radiation from the second waveguide of the waveguiding first arrangement. a waveguiding first arrangement which is configured to provide at least one electromagnetic radiation; a configuration which is configured to receive and split the at least one electromagnetic radiation into a first radiation and a second radiation; a waveguiding second arrangement (120, 202, 208) which includes a first waveguide and a second waveguide (120, 202), wherein the first waveguide is configured to receive the first radiation, and the second waveguide (120, 202) is configured to receive the second radiation; a fiber coupler arrangement (316, 416); and a rotary junction (318, 418) coupled to the fiber coupler arrangement (316, 416); wherein the waveguiding first arrangement, the waveguiding second arrangement (202, 208), and the configuration are housed in a probe (320, 424), the waveguiding first arrangement comprising a first waveguide and a second waveguide, wherein the first waveguide is a core of an optical fiber, said fiber comprising at least two claddings, and the second waveguide is an inner cladding of the optical fiber; wherein the first waveguide of the waveguiding second arrangement (120, 202, 208) is a core of a first optical fiber and the second waveguide (120, 202) of the waveguiding second arrangement (120, 202, 208) is an optical fibre; wherein the configuration comprises an optics arrangement (106, 116) provided at the end of the waveguiding second arrangement (120, 202. 208); and wherein the first radiation is based on radiation from an OCT radiation source (302, 402) and the second radiation is based on radiation from a diffuse spectroscopy light source both of which are configured to illuminate at least one structure; wherein, the optics arrangement (106, 116) is configured to receive the first and second radiations from the at least one structure; wherein, the first radiation is provided to the first waveguide of the waveguiding first arrangement and the second radiation is provided to the second waveguide of the waveguiding first arrangement; and wherein, the fiber coupler arrangement (316, 416) is configured to extract the second radiation from the second waveguide of the waveguiding first arrangement.