Abstract
Broadly tunable upconversion is demonstrated for long-wave infrared (LWIR) detection. The upconversion system is evaluated by the detection of 50 ns pulses from a narrow linewidth tunable quantum cascade laser (QCL) in the 9.4 to 12 µm range. The LWIR signal is mixed with a 1064 nm laser beam in a silver gallium sulfide (AgGaS2) crystal, resulting in an upconverted signal in the 956 to 977 nm range, using angle tuning for optimal phase-matching. This allows for efficient, high speed detection using a standard silicon detector. A theoretical model including absorption and diffraction shows qualitative agreement with experimental data.
Highlights
Many substances can be identified by their spectral features associated with fundamental rotational and vibrational absorption bands in the infrared spectral region
Broadly tunable upconversion is demonstrated for long-wave infrared (LWIR) detection
The upconversion system is evaluated by the detection of 50 ns pulses from a narrow linewidth tunable quantum cascade laser (QCL) in the 9.4 to 12 μm range
Summary
Many substances can be identified by their spectral features associated with fundamental rotational and vibrational absorption bands in the infrared spectral region. This has spurred much attention to infrared (IR) technologies relating to applications, such as infrared spectroscopy [1,2,3,4] and infrared hyperspectral imaging [5,6,7,8]. Cooling is required to optimize the performance of traditional LWIR detectors, but it generally makes them bulky, expensive and inconvenient to use. The lack of cheap, efficient detectors in the LWIR range has to some extent prevented widespread use of IR spectroscopy
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
