The atomic vapor quantum counter (AVQC) offers the potential for efficient upconversion of narrow-band IR radiation. This paper explores wavelength tuning of the AVQC by the application of an electric field (Stark effect). Model calculations indicate the Stark effect in combination with the proper selection of IR transitions in the atomic vapor can yield continuous tuning across the entire

m spectral region. Experimental results near 10 μm have demonstrated over 23 cm
-1tuning on a single potassium vapor transition. Thirteen CO
2laser wavelengths were scanned in this fashion.