Evidence is shown that spherical structures of methyloctadecaoate nucleated from a Langmuir monolayer in a laser focus are giant multilamellar bubbles. The bubbles remain stable in the laser focus but respread to the monolayer outside of the focus. Bubbles coalesce when brought into contact. The coalescence is accompanied by a volume increase and area decrease of the fused bubble as compared to the original pair of bubbles. Bubbles deviate from spherical and are compressed along the flow direction of the surrounding monolayer when they are advected versus and trapped at phase boundaries of the monolayer.