Toward Extended-Cavity Grating-Tuned Mid-Infrared Diode Laser Operation

摘要

The authors have investigated an extended-cavity technique which utilizes tunablelead-salt diode lasers, emitting in the spectral region around 3 micro m. The authors have developed a special liquid-nitrogen cryostat that enables them to place both the collimation optics and the optics for the extended cavity within the vaccum chamber. The external reflector is a diffraction grating for wavelength-selective optical feedback. This scheme promises to overcome two major drawbacks of tunable diode lasers, their large spectral width and their incomplete spectral coverage. Progress with the coating efforts, problems with the collimation optics, and establishment of procedures for determining optimum feedback are discussed.