Waveguide-based single-pixel up-conversion infrared spectrometer

A periodically poled lithium niobate (PPLN) waveguide-based single-pixel up-conversion infrared spectrometer was demonstrated. Sum-frequency generation between a 1.5-μm-band scanning pump laser and a 1.3-μm-band signal generated visible radiation which was detected by a silicon single-photon detector. The up-conversion spectrometer’s sensitivity was two-orders-of-magnitude higher than that of a commercial optical spectrum analyzer.