Petal-like beam generation by multiplexing OAM modes from a mode-shifting recirculating loop

Structured light plays a key role in advancing applications such as optical communication, imaging, and sensing. Among various beam-shaping techniques, the generation of petal-like intensity profiles by combining orbital angular momentum (OAM) modes has received increased attention. While conventional petal-like intensity profile beam generation approaches typically rely on spatial light modulators or metamaterials, this paper explores an alternative method based on the OAM mode-shifting recirculating loop. The proposed loop comprises an optical coupler, a set of mirrors, and an OAM mode shifter, enabling the input beam to circulate and accumulate gradual additional OAM shifts. When the light reaches the coupler after every round trip, a portion of the recirculating modes exits the loop. By coherently superposing these output OAM modes, we demonstrate, in simulation, the possibility of generating petal-like beams under different loop configurations.