Responsivity and Noise Equivalent Power of a Single Cold-Electron Bolometer

We have developed a single-pixel capacitively coupled Cold-Electron Bolometer (CEB) and characterized it in the current-biased regime. The most attractive feature of the CEB is effective electron self-cooling of the absorber, which leads to a lower bolometer noise and higher dynamic range. The bolometer responsivity was measured by determining the voltage response to an applied power through the absorber from a heating current, modulated at frequencies from 35 Hz to 2 kHz. The optimum responsivity of 1.5 x 10(10) V/W was measured at a modulation frequency of 35 Hz. The noise equivalent power (NEP) was subsequently obtained from the estimated bolometer noise voltage with respect to the measured bolometer responsivity. The NEP of better 2 x 10(-18) W/Hz(1/2) was obtained for modulation frequencies greater than 100 Hz. The background power and the bolometer time constant were also estimated from the experimental results. The photon-noise-limited operation of CEB will dominate for a signal power of 10 fW and higher at frequency 80 GHz and higher.

Automated summary

A single-pixel capacitively coupled Cold-Electron Bolometer (CEB) was developed and characterized in the current-biased regime, showing effective electron self-cooling for lower noise and higher dynamic range. The bolometer responsivity and noise equivalent power (NEP) were measured, with the best performance observed at modulation frequencies above 100 Hz. The study indicates photon-noise-limited operation of CEB for signal powers of 10 fW and higher at frequencies of 80 GHz and above.