His later films adopted a form of poetic realism influenced by pictorialist photography.

Following a serious accident, he withdrew from theatrical productions and accepted a contract from Gaumont to make a film.

In 1914 with the outbreak of war, he joined the army and became a lieutenant in the artillery, even though his accident exempted him from duty.

At the end of the conflict he returned to filmmaking, creating a large number of films in the silent era, but reducing his output after the advent of sound.

Poirier utilised, ten years after the conflict, the battlefield and the ruins of the forts of Vaux and Douaumont.