A device, comprising: an optical fiber to provide electromagnetic radiation; a prism adapted to reflect a portion of the electromagnetic radiation to generate a reflected portion of the electromagnetic radiation, wherein the prism is adapted to be immersed in a multiphase fluid and an end of the optical fiber is in direct physical contact with a base of the prism, the reflected portion being reflected by the prism into the optical fiber; and a processing subsystem adapted to analyze the multiphase fluid based upon at least a portion of the reflected portion of the electromagnetic radiation; wherein the optical fiber is not in direct physical contact with the multiphase fluid; the device being characterised in that it comprises a holding device comprising: - a holder adapted to hold the prism, said holder comprising a holder hole; - a male connector adapted to hold the optical fiber and comprising a first male extension having a shape and size such that the first male extension is inserted into the holder hole; and wherein the holder hole has a shape and size such that when the first male extension is inserted into the holder hole, an equal distance is maintained between the outer surface of the first male extension and the inner surface of the holder hole; and wherein said holding device is configured to align a principal optical axis of the optical fiber with a principal optical axis of the prism such that: (a) the principal optical axis of the prism and the principal optical axis of the optical fiber are parallel and substantially fall on a single straight line; or (b) the principal optical axis of the prism and the principal optical axis of the optical fiber are parallel, and a distance between the principal optical axis of the prism and the principal optical axis of the optical fiber is in the range of about 0 to 30 micron. an optical fiber to provide electromagnetic radiation; a prism adapted to reflect a portion of the electromagnetic radiation to generate a reflected portion of the electromagnetic radiation, wherein the prism is adapted to be immersed in a multiphase fluid and an end of the optical fiber is in direct physical contact with a base of the prism, the reflected portion being reflected by the prism into the optical fiber; and a processing subsystem adapted to analyze the multiphase fluid based upon at least a portion of the reflected portion of the electromagnetic radiation; wherein the optical fiber is not in direct physical contact with the multiphase fluid; the device being characterised in that it comprises a holding device comprising: - a holder adapted to hold the prism, said holder comprising a holder hole; - a male connector adapted to hold the optical fiber and comprising a first male extension having a shape and size such that the first male extension is inserted into the holder hole; and - a holder adapted to hold the prism, said holder comprising a holder hole; - a male connector adapted to hold the optical fiber and comprising a first male extension having a shape and size such that the first male extension is inserted into the holder hole; and wherein the holder hole has a shape and size such that when the first male extension is inserted into the holder hole, an equal distance is maintained between the outer surface of the first male extension and the inner surface of the holder hole; and wherein said holding device is configured to align a principal optical axis of the optical fiber with a principal optical axis of the prism such that: (a) the principal optical axis of the prism and the principal optical axis of the optical fiber are parallel and substantially fall on a single straight line; or (b) the principal optical axis of the prism and the principal optical axis of the optical fiber are parallel, and a distance between the principal optical axis of the prism and the principal optical axis of the optical fiber is in the range of about 0 to 30 micron. (a) the principal optical axis of the prism and the principal optical axis of the optical fiber are parallel and substantially fall on a single straight line; or (b) the principal optical axis of the prism and the principal optical axis of the optical fiber are parallel, and a distance between the principal optical axis of the prism and the principal optical axis of the optical fiber is in the range of about 0 to 30 micron.