The Need of Terahertz Cameras for Standardizing Sensitivity Measurements

作者：Oda Naoki^*; Hosako Iwao; Ishi Tsutomu; Minamide Hiroaki; Otani Chiko; Sekine Norihiko

来源：Journal of Infrared Millimeter and Terahertz Waves, 2014, 35(8): 671-685.

DOI：10.1007/s10762-014-0073-0

• Terahertz
• Uncooled focal plane array
• Minimumdetectable power (MDP)
• Non-uniformity correction

The applicability of a blackbody source to sensitivity measurements and calibration of an uncooled Terahertz (THz) focal plane array (FPA) is discussed, but the combination of a blackbody source and a band-pass filter may not be suitable for these purposes. Two ways to measure the minimum detectable power (MDP) of uncooled THz-FPAs are described and compared when used with strong THz sources such as a quantum cascade laser (QCL). The MDP is defined as the radiant power that produces a signal-to-noise ratio of unity in the output of a THz imager that uses a THz-FPA operating at a TV frame rate. One method (method 1) is based on the hypothesis that the beam pattern of the THz source is close to a Gaussian pattern. In another method (method 2), the signal level of the background in an image that does not contain a THz source is subtracted from the signal of the image. While method 2 is more flexible, how large the signals coming from THz source should be, as compared with the noise level, remains to be defined. Finally, based on issues with the current non-uniformity correction (NUC) technique, specifications are proposed for THz source power and wobbling technique to obtain uniform illumination for an ideal NUC technique.

• 出版日期2014-8
• 单位RIKEN