Single-frequency mid-infrared laser light source

The invention relates to a single-frequency mid-infrared laser light source. The single-frequency mid-infrared laser light source comprises a 1,064-nm module, 1,550-nm module, an optical parameter conversion module and a detection feedback module, 1,064-nm pump light output by the 1,064-nm module and 1,550-nm signal light output by the 1,550-nm module are subjected to difference frequency processing through the optical parameter conversion module, 3.4-micrometer mid-infrared laser is output, the detection feedback module receives an optical parameter conversion module output signal, 638-nm red light resolved from the 3.4-micrometer mid-infrared laser serves as a detection signal, the rest 3.4-micrometer mid-infrared laser is filtered and output, the detection feedback module takes a 638-nm red light power change value as a feedback signal which returns to pump sources in the 1,064-nm module and the 1,550-nm module, the output power of the 1,064-nm module and the output power of the 1,550-nm module are adjuste