= Rodney W. Leonhardt
{c}
\b[Rodney W. Leonhardt] is the author of a2004 <National Institute of Standards and Technology> report on <measurement calibration> of low-level pulsed-laser radiometers at a <wavelength> of1.06micrometres. It treats <laser pulse energy> and <peak power> as separate measurement quantities and describes the apparatus and <measurement uncertainty> needed to transfer a laboratory reference to a test instrument.<Calibration Service for Low-level Pulsed-Laser Radiometers at 1.06 µm: Pulse Energy and Peak Power by Rodney W. Leonhardt>[NIST SP250-64, title/byline and §§3–5]{ref}
The pulse-energy procedure uses a modulated laser, a calibrated <beam splitter> arrangement, a relatively slow thermal reference and a fast test radiometer. The reference accumulates energy over many pulses. Pulse repetition rate and the illumination interval determine the pulse count; the splitter ratio transfers the reference energy to the lower-energy test beam. The thermal detector need not resolve individual pulses.<Calibration Service for Low-level Pulsed-Laser Radiometers at 1.06 µm: Pulse Energy and Peak Power by Rodney W. Leonhardt>[§4, printed pp9–10]{ref}
For an original idealized transfer calculation, let the reference receive a total $E_{\rm ref}=1\,\mu\mathrm J$ over $N=1000$ equal pulses. Define $B=100$ as the reference-to-test beam energy ratio. The average energy per test pulse is
$$
U_{\rm test}=\frac{E_{\rm ref}}{BN}
=\frac{10^{-6}}{100\times1000}\,\mathrm J=10\,\mathrm{pJ}.
$$
If the calibrated radiometer's selected output measure is0.20volts, the corresponding energy-per-output coefficient would be50picojoules per volt. These invented values explain the transfer arithmetic and do not reproduce the report's calibration results.
The output measure must be specified together with its coefficient. Leonhardt's report discusses offsets in the integrating-amplifier waveform and use of peak-to-peak <electric potential difference> as a readout. Its peak-power procedure separately compares continuous and pulsed conditions.<Calibration Service for Low-level Pulsed-Laser Radiometers at 1.06 µm: Pulse Energy and Peak Power by Rodney W. Leonhardt>[§4, waveform/offset discussion; §5.1, peak-power comparison]{ref} The work illustrates how a measurement becomes reproducible by recording the optical transfer and electrical readout conventions, rather than only stating a detector sensitivity.
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