A ytterbium-doped silica microcavity laser demonstrates stable laser emission while completely submerged in water. To our knowledge, it is the first solid-state laser whose cavity mode interacts with water. The device generates more than 2 microW of output power. The laser performance is presented, and low-concentration biosensing is discussed as a potential application.

A solid-state laser based on a dye-doped deoxyribonucleic acid (DNA) matrix is described. A thin solid film of DNA has been fabricated by treating with polyvinyl alcohol (PVA) and used as a host for the laser dye Rhodamine 6G. The edge emitted spectrum clearly indicated the existence of laser modes and amplified spontaneous emission. Lasing was obtained by pumping with a frequency-doubled Nd:YA...