Laser-Excited Optical Filters: Laser Power Requirements

Narrow bandwidth optical sources are readily available. However, tunable narrow bandwidth, wide field-of-view optical filters are not available. The laser-excited optical filters (LEOF) presented here are in principle tunable narrow bandwidth, wide field-of-view optical filters. These filters can simultaneously provide high resolution (0.001 nm), wide field-of-view (2π), high quantum efficiency, and electrically tunable optical filtering. Narrow bandwidth operation of laser-pumped atomic vapor filters were first demonstrated by Gelbwachs et al1., by Marling et al.2, and recently by Chung et al.3 The first electrical tuning of these devices was demonstrated by Gelbwachs et. al.4 In addition, alkali vapor based LEOFs can operate on 130 transitions between 921 and 474 nm. LEOFs are ideally suited for extracting weak narrow bandwidth signals buried in strong nonresonant optical background radiation. Potential applications of these filters include laser radar, laser communications, detection of Raman radiation, atomic spectroscopy, etc.