Polen left his fifth year of medical school to follow his passion for filmmaking. Because of the absence of film schools in Cambodia, he taught himself filmmaking by watching and studying films. Inspired by a love of literature, Polen has written and directed short films and documentaries, and often uses small details from daily life as tools of metaphorical storytelling. In 2015, his short film Colourful Knots won the first prize at Tropfest SEA in Malaysia. His other film Red Ink (2016) earned him recognition on national and international stages, including Tokyo International Film Festival and Tehran International Short Film Festival. Currently Polen is developing his debut feature film project entitled Ink, a sci-fi drama mystery about a dictatorial island.