This thesis describes the work performed at the Quantum Optics lab at UNAM,Mexico City. Third order spontaneous parametric down conversion (TOSPDC) isa quantum optical process where an incoming photon is annihilated and generatesthree quantum entangled photons, so called photon triplets, under energy and mo-mentum conservation. This TOSPDC process was experimentally realized using afused silica optical fiber as nonlinear source. The spectra of the emitted signal weremeasured and coincidence counts measurements were performed in order to verifythe generation of these triplets. An average of 0.8 triplets per second were detected,which is the first sign of a realized TOSPDC process to our knowledge. At thispoint, the signal was too low for any spectra to be recorded. There is a lot of roomfor improvements, especially regarding the equipment used due to the heavy signalloss throughout the experimental setup, and more experiments will be performed toproperly verify the production and entanglement of the triplet photons.