Benefits of bolometer Joule stepping and Joule pulsing
  We introduce the `Joule stepping' technique, whereupon a constantly-biased
bolometer has its bias voltage modified by a small additional step. We
demonstrate this technique using a composite NTD semiconductor bolometer and a
pulsing device which sends an extra step in voltage. We demonstrate the results
of the technique over a range of bias voltages at 100, 200, and 300 mK. We find
that Joule stepping allows us to directly measure long thermal tails with low
amplitudes in the bolometer response, and could be a useful tool for quickly
and easily understanding response functions of bolometric detectors. We also
show that the derivative of the Joule step is equivalent to the bolometer
response to a $\delta$-pulse (or Joule pulse), which allows for greater
understanding of fast transient behaviour.
