Flexible polymer colloidal-crystal lasers with a light-emitting planar defect

Flexible polymer laser devices excited by low-threshold optical light are fabricated from colloidal crystals (CCs; see figure). The laser-cavity structure consists of a light-emitting layer sandwiched between two polymer CC films. Optical excitation with a green beam brings about emission with a red beam. This process allows the production of ultralightweight, low-cost, flexible, and easily processible all-plastic lasers.