The invention provides an optical component weak absorption test device and method based on the
equivalent temperature. The method is characterized in that firstly, a sample is irradiated with pump
laser, after a
steady state is realized, the highest temperature of the sample surface is recorded through utilizing an
infrared thermal imager, and reflection and transmission powers of the sample aretested through utilizing a pump light power meter; secondly, a probing
laser is utilized to (a CO2
laser, the spot size is the same as that of the pump laser spot) irradiate the surface of the sample,generally, an
absorption rate of CO2 for an optical element such as a
dielectric film is 1, the probing laser power is increased gradually to make the surface temperature of the sample reach the temperature of a first test, at this time, the power in a probing light power meter is read; and lastly, the sum of ratios of the reading of the probing light power meter to the reflection and transmission powers of the sample is the weak
absorption rate of the sample surface. The method is advantaged in that the
absorption rate of the CO2 laser is mainly 1 through utilizing a general optical element,the temperature characteristics of the sample under pump
light irradiation are utilized to test the weak absorption rate of the surface, compared with technical tests in the prior art, not only precision is high, but also operation is simpler and more convenient, and no post-
data processing is required.