Laser ignited pre-combustion chamber assembly

The present disclosure relates to a laser ignited pre-combustion chamber assembly (20) for gaseous fuel internal combustion engines. The pre-combustion chamber assembly (20) may comprise a plurality of flow transfer passages (28, 28A, 28B) fluidly connecting a pre-combustion chamber (26) to a main combustion chamber (8) and each defining an inflow direction for combustion mixture, and an optical window (34) of a laser ignition device (30). Each of the inflow directions may pass by the optical window (34) for preventing the optical window (34) from being directly blown at by the combustion mixture entering the pre-combustion chamber (28) via the plurality of flow transfer passages (28, 28A, 28B).