Lecture 10: Bolometers - Leiden Observatory
Lecture 10: Bolometers - Leiden Observatory
Lecture 10: Bolometers - Leiden Observatory
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Johnson noise:<br />
Thermal noise:<br />
Photon noise:<br />
TOTAL NEP NOISE:<br />
Detection of Light: <strong>Lecture</strong> <strong>10</strong><br />
The total NEP<br />
NEPJ ⇡<br />
NEPT = (4kT 2 G) 1/2<br />
NEPphoton = hc<br />
⇥<br />
GT 2 for (T ) ⇡ T 3/2<br />
GT 3/2 for (T ) ⇡ T 1<br />
....due to fluctuations in the thermal motions of charge carriers<br />
(random currents due to Brownian motion)<br />
due to fluctuations of entropy across the thermal link that<br />
connects the detector and the heat sink.<br />
✓ 2⇤ ◆ 1/2<br />
...due to fluctuations in the photon flux<br />
NOTE: <strong>Bolometers</strong> DO NOT HAVE G-R noise<br />
(remember: no particle pairs created/destroyed)<br />
NEP = p (NEP 2 photon + NEP 2 + NEP 2 J + ...)