Room-Temperature Characterization of Mid-Infrared Up-Conversion Detection

Mid-infrared (MIR) detection technology is crucial in advancing scientific exploration in life sciences and physical analysis, as well as in practical applications in environmental protection, the chemical industry, and medical diagnostics. By analyzing the advantages and disadvantages of these two detection methods the difference-frequency generation (DFG)/the sum-frequency generation (SFG), this article offers guidance for selecting and optimizing MIR detection methods. When the MIR attenuation multiplier is small (indicating a large signal), DFG can obtain a larger up-converted signal by increasing the length of the crystal or pumping energy. In contrast, when the MIR attenuation is significant, the SFG is easier to distinguish the signal and the readability is better. SFG demonstrates over an order of magnitude improvement compared to DFG and enables detection at the 100-photon level. In addition, this article presents the room-temperature characterization of MIR up-conversion detection and establishes a foundation for the application of up-conversion detection in various fields.