Analysis of optical properties of cell lasers and their use as biological sensors

We analyzed single-cell lasers made from different cell types and a variety of organic fluorescent dyes commonly employed for staining cells. Adherent cells or cell suspension is placed in between two highly reflective dielectric mirrors, which form a laser cavity. The rounded shape of the cell acts as a lens making a stable laser cavity. The resonator stability is dependent on the resonator gap, cell size and refractive index. We investigated the effects of gain dye distribution inside and outside the cells. The cell laser thresholds were calculated to optimize the dye concentration, resonator gap and selection of the dye. The different transversal cell laser modes are dependent on cell shape and refractive index distribution. By measuring the laser modes we demonstrate single cell shape characterization and sensing.