Mode-locked lasers for high-accuracy radiometry

The use of a mode-locked laser as a source for high-accuracy calibration of transfer standards to a cryogenic radiometer is discussed. The critical issue is the relative response of the transfer standard to the modelocked laser light as compared with continuous-wave laser light. As a first test, we have measured the linearity of the response of silicon photodiode light-trapping detectors using mode-locked laser light at a wavelength of 532 nm.