Flexible and tensile microporous polymer fibers for wavelength-tunable random lasing

Flexible and tensile wavelength-tunable micrometer-sized random lasers in the form of microporous polymer fiber are demonstrated. The fibers are fabricated by directly drawing from an aqueous mixture and subsequently selective chemical etching in a green solvent. Size-dependent lasing threshold and spectrum are investigated. Owing to mechanical flexibility, wavelength-tuning of 5.5 nm is achieved by stretching the fiber.