An Ultrasonic Absolute Power Transfer Standard

Absolute Ultrasonic Measurements with Piezoelectric Transducers

The absolute calibration of a piezoelectric transducer refers to the determination of the relationship between the electrical and acoustical quantities for a transducer coupled to a solid. It is shown how a well-characterized ultrasonic system, consisting of source,structure and receiver can be used to make such measurements for transducers operating as sources or receivers. Results are given, ...

Tests of an omnipresent standard for absolute spectral radiance measurements

Correlated pairs of photons can be used to access what is effectively an omnipresent absolute standard of spectral radiance. The process of spontaneous parametric downconversion, in which pump photons are converted into pairs of photons, can be thought of as being stimulated by an omnipresent and omnidirectional one photon per mode vacuum background. This background has units of spectral radian...

Development of an Inverse Ultrasonic Radiative Transfer Technique

Intercomparison of the LBIR Absolute Cryogenic Radiometers to the NIST Optical Power Measurement Standard

The Low Background Infrared calibration (LBIR) facility at the National Institute of Standards and Technology (NIST) presently maintains four absolute cryogenic radiometers (ACRs) which serve as standard reference detectors for infrared calibrations performed by the facility. The primary standard for optical power measurements at NIST-Gaithersburg has been the High Accuracy Cryogenic Radiometer...

PicoWatt infrared power measurement using an absolute cryogenic radiometer

We report on initial measurements of the low-temperature thermal properties of a device that is similar to the experimental apparatus used for absolute cryogenic radiometry (ACR) within the Low Background InfraRed (LBIR) facility at NIST. The device consists of a receiver cavity mechanically and thermally connected to a temperature-controlled stage through a thin-walled polyimide tube which ser...