IR microcavity light emitters for gas detection

Summary form only given. Optical gas monitoring would require light sources above 3 /spl mu/m because most of the gas species (CO, CO/sub 2/, NO/sub x/, HCl, SO/sub 2/, N/sub 2/O, NH/sub 3/, CH/sub 4/...) have their fundamental absorption lines between 3 and 6 /spl mu/m. We report here on resonant microcavity light sources emitting at room temperature between 2 /spl mu/m and 6 /spl mu/m. The emitter combines a CdHgTe light-emitting active heterostructure layer including a multiple quantum well, grown by molecular beam epitaxy, and two evaporated YF/sub 3/-ZnS multilayered Bragg mirrors.