Two-photon pumped up-conversion

In order to test the two-photon pumped, up-conversion lasing performance of this polymer, a polymer rod of 13 mm length with two polished ends was prepared. This polymer rod was placed in a 20 mm long glass cell filled with a refractive index-matching transparent liquid to reduce the influence of the non-optical polishing quality of the two ends [92]. The 1064 nm pumping beam provided by... 

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