Temperature control of laser action in scattering media

Summary form only given. Our system is comprised of hydroxypropyl cellulose (HPC) with a nominal average molecular weight of 370,000 dissolved in deionized water. HPC is a FDA-approved, nonionic, water-soluble cellulose derivative possessing lower critical soluble temperature (LCST) in water. When a laser dye with high gain is dissolved into this system, it makes a nice random laser system where scattering length and photon diffusivity can be temperature-controlled. We used Kiton Red 620 as laser dye and pumped with 7 ns-long 532 nm laser pulse.